imx8mq_pins: fix configuration for UART4 on ECSPI2 pads

When routing UART4 using the ECSPI2 pads, register
IOMUXC_UART4_RXD_SELECT_INPUT (offset 0x050C) should be changed only
when dealing with RX, as its name suggests.

arch/arm/include/asm/arch-imx8m/imx8mq_pins.h

@@ -538,7 +538,7 @@ enum {
 		IMX8MQ_PAD_ECSPI2_SCLK__GPIO5_IO10                  = IOMUX_PAD(0x046C, 0x0204, 5, 0x0000, 0, 0),
 
 		IMX8MQ_PAD_ECSPI2_MOSI__ECSPI2_MOSI                 = IOMUX_PAD(0x0470, 0x0208, 0, 0x0000, 0, 0),
-		IMX8MQ_PAD_ECSPI2_MOSI__UART4_TX                    = IOMUX_PAD(0x0470, 0x0208, 1, 0x050C, 1, 0),
+		IMX8MQ_PAD_ECSPI2_MOSI__UART4_TX                    = IOMUX_PAD(0x0470, 0x0208, 1, 0x0000, 0, 0),
 		IMX8MQ_PAD_ECSPI2_MOSI__GPIO5_IO11                  = IOMUX_PAD(0x0470, 0x0208, 5, 0x0000, 0, 0),
 
 		IMX8MQ_PAD_ECSPI2_MISO__ECSPI2_MISO                 = IOMUX_PAD(0x0474, 0x020C, 0, 0x0000, 0, 0),