pitx-imx8m: fix UART RTS/CTS lines for rev2 and rev3 boards

- add setup for UART3 RTS and CTS lines.
- check hw revision and swap RTS and CTS lines for old rev2 modules.
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

board/kontron/pitx-imx8m/pitx-imx8m.c

@@ -88,6 +88,8 @@ int board_qspi_init(void)
 static iomux_v3_cfg_t const uart_pads[] = {
 	IMX8MQ_PAD_UART3_RXD__UART3_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
 	IMX8MQ_PAD_UART3_TXD__UART3_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
+	IMX8MQ_PAD_ECSPI1_SS0__UART3_RTS_B | MUX_PAD_CTRL(UART_PAD_CTRL),
+	IMX8MQ_PAD_ECSPI1_MISO__UART3_CTS_B | MUX_PAD_CTRL(UART_PAD_CTRL),
 };
 
 int board_early_init_f(void)
@@ -491,8 +493,13 @@ int board_mmc_get_env_dev(int devno)
 #define TPM_RESET    IMX_GPIO_NR(3, 2)
 #define USBHUB_RESET IMX_GPIO_NR(3, 4)
 
+#define IMX8MQ_PAD_ECSPI1_MISO__UART3_RTS_B	IOMUX_PAD(0x0464, 0x01FC, 1, 0x0500, 0, UART_PAD_CTRL)
+#define IMX8MQ_PAD_ECSPI1_SS0__UART3_CTS_B	IOMUX_PAD(0x0468, 0x0200, 1, 0x0000, 0, UART_PAD_CTRL)
+
 int misc_init_r(void)
 {
+	int hw_rev;
+
 #ifdef CONFIG_EMB_EEP_SPI
 	emb_vpd_init_r();
 #endif
@@ -523,7 +530,12 @@ int misc_init_r(void)
 	udelay(10000);
 	gpio_direction_output(USBHUB_RESET, 1);
 
-	board_gpio_init();
+	hw_rev = get_hw_rev();
+	/* check if hw variant is L120 (7) */
+	if (hw_rev == 7) {
+		imx_iomux_v3_setup_pad(IMX8MQ_PAD_ECSPI1_MISO__UART3_RTS_B);
+		imx_iomux_v3_setup_pad(IMX8MQ_PAD_ECSPI1_SS0__UART3_CTS_B);
+	}
 
 	return 0;
 }