mimxrt/machine_uart: Enable CTS SION so it can be read.

The new CYW43 BTHCI UART backend requires CTS pin to be defined and
readable.  This patch enables the CTS pin SION bit to allow it to be read
regardless of mux mode.

Signed-off-by: iabdalkader <i.abdalkader@gmail.com>

Author: iabdalkader

ports/mimxrt/machine_uart.c

@@ -136,7 +136,7 @@ bool lpuart_set_iomux_cts(int8_t uart) {
     int index = (uart - 1) * 2;
 
     if (CTS.muxRegister != 0) {
-        IOMUXC_SetPinMux(CTS.muxRegister, CTS.muxMode, CTS.inputRegister, CTS.inputDaisy, CTS.configRegister, 0U);
+        IOMUXC_SetPinMux(CTS.muxRegister, CTS.muxMode, CTS.inputRegister, CTS.inputDaisy, CTS.configRegister, 1U);
         IOMUXC_SetPinConfig(CTS.muxRegister, CTS.muxMode, CTS.inputRegister, CTS.inputDaisy, CTS.configRegister,
             pin_generate_config(PIN_PULL_UP_100K, PIN_MODE_IN, PIN_DRIVE_6, CTS.configRegister));
         return true;