how to instruct vivado not to add I/O Buffers.

module top(
     input sys_clk,  //(* io_buffer_type = "NONE" *)
    output tx,
    input rx
    );
//(* IOB = "true" *)
(* IOB = "false" *) reg [51:0] count = 0; 
(* IOB = "false" *) reg reset = 0; 

design_1_wrapper microBlaze(.clk(sys_clk),.rst(reset),.uart_rtl_rxd(rx),.uart_rtl_txd(tx));   

always @(posedge sys_clk)
    begin
        count <= count + 1 ;
        if ( count > 52'h3 && count < 52'h00F )
            begin
                reset <= 0;
            end
        else
            begin
                reset <= 1 ;
            end
    end
    
endmodule

[Synth 8-5535] port <sys_clk> has illegal connections. It is illegal to have a port connected to an input buffer and other components. The following are the port connections :
Input Buffer:
	Port I of instance clkin1_ibufg(IBUF) in module <design_1_clk_wiz_1_0_clk_wiz>
Other Components:
	Port C of instance reset_reg(FD) in module top
	Port C of instance \count_reg[51] (FD) in module top
	Port C of instance \count_reg[50] (FD) in module top
	Port C of instance \count_reg[49] (FD) in module top
	Port C of instance \count_reg[48] (FD) in module top
	Port C of instance \count_reg[47] (FD) in module top
	Port C of instance \count_reg[46] (FD) in module top
	Port C of instance \count_reg[45] (FD) in module top
	Port C of instance \count_reg[44] (FD) in module top
	Port C of instance \count_reg[43] (FD) in module top
	Port C of instance \count_reg[42] (FD) in module top
	Port C of instance \count_reg[41] (FD) in module top
	Port C of instance \count_reg[40] (FD) in module top
	Port C of instance \count_reg[39] (FD) in module top
	Port C of instance \count_reg[38] (FD) in module top
	Port C of instance \count_reg[37] (FD) in module top
	Port C of instance \count_reg[36] (FD) in module top
	Port C of instance \count_reg[35] (FD) in module top
	Port C of instance \count_reg[34] (FD) in module top
	Port C of instance \count_reg[33] (FD) in module top
	Port C of instance \count_reg[32] (FD) in module top
	Port C of instance \count_reg[31] (FD) in module top
	Port C of instance \count_reg[30] (FD) in module top
	Port C of instance \count_reg[29] (FD) in module top
	Port C of instance \count_reg[28] (FD) in module top
	Port C of instance \count_reg[27] (FD) in module top
	Port C of instance \count_reg[26] (FD) in module top
	Port C of instance \count_reg[25] (FD) in module top
	Port C of instance \count_reg[24] (FD) in module top
	Port C of instance \count_reg[23] (FD) in module top
	Port C of instance \count_reg[22] (FD) in module top
	Port C of instance \count_reg[21] (FD) in module top
	Port C of instance \count_reg[20] (FD) in module top
	Port C of instance \count_reg[19] (FD) in module top
	Port C of instance \count_reg[18] (FD) in module top
	Port C of instance \count_reg[17] (FD) in module top
	Port C of instance \count_reg[16] (FD) in module top
	Port C of instance \count_reg[15] (FD) in module top
	Port C of instance \count_reg[14] (FD) in module top
	Port C of instance \count_reg[13] (FD) in module top
	Port C of instance \count_reg[12] (FD) in module top
	Port C of instance \count_reg[11] (FD) in module top
	Port C of instance \count_reg[10] (FD) in module top
	Port C of instance \count_reg[9] (FD) in module top
	Port C of instance \count_reg[8] (FD) in module top
	Port C of instance \count_reg[7] (FD) in module top
	Port C of instance \count_reg[6] (FD) in module top
	Port C of instance \count_reg[5] (FD) in module top
	Port C of instance \count_reg[4] (FD) in module top
	Port C of instance \count_reg[3] (FD) in module top
	Port C of instance \count_reg[2] (FD) in module top
	Port C of instance \count_reg[1] (FD) in module top
	Port C of instance \count_reg[0] (FD) in module top

set_property PACKAGE_PIN D10 [get_ports rx]
#set_property IOSTANDARD LVCMOS33 [get_ports rx]
set_property PACKAGE_PIN D11 [get_ports tx]
#set_property IOSTANDARD LVCMOS33 [get_ports tx]
#set_property IOSTANDARD LVCMOS33 [get_ports sys_clk]
set_property PACKAGE_PIN AA23 [get_ports sys_clk]
#create_clock -period 20.00 -name sys_clk [get_ports sys_clk]
#set_property BITSTREAM.CONFIG.UNUSEDPIN PULLUP [current_design]