imx: imx8mp_rsb7320a1: enable wdog driver model in SPL

Mark wdog1/pinctrl_wdog as u-boot,dm-spl to clean up board code,

The set_wdog_reset() function is not necessary as this is handled by
the imx_watchdog.c driver due to the 'fsl,ext-reset-output' property
being set.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/dts/imx8mp-rsb3720-a1-u-boot.dtsi b/arch/arm/dts/imx8mp-rsb3720-a1-u-boot.dtsi
index 2848b24..4419967 100644
--- a/arch/arm/dts/imx8mp-rsb3720-a1-u-boot.dtsi
+++ b/arch/arm/dts/imx8mp-rsb3720-a1-u-boot.dtsi
@@ -89,6 +89,14 @@
 	u-boot,dm-spl;
 };
 
+&wdog1 {
+	u-boot,dm-spl;
+};
+
+&pinctrl_wdog {
+	u-boot,dm-spl;
+};
+
 &pinctrl_i2c1 {
 	u-boot,dm-spl;
 };
diff --git a/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c b/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c
index f129ebd..0a1b2c9 100644
--- a/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c
+++ b/board/advantech/imx8mp_rsb3720a1/imx8mp_rsb3720a1.c
@@ -28,12 +28,6 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-#define WDOG_PAD_CTRL	(PAD_CTL_DSE6 | PAD_CTL_ODE | PAD_CTL_PUE | PAD_CTL_PE)
-
-static const iomux_v3_cfg_t wdog_pads[] = {
-	MX8MP_PAD_GPIO1_IO02__WDOG1_WDOG_B  | MUX_PAD_CTRL(WDOG_PAD_CTRL),
-};
-
 #ifdef CONFIG_NAND_MXS
 static void setup_gpmi_nand(void)
 {
@@ -69,12 +63,6 @@
 
 int board_early_init_f(void)
 {
-	struct wdog_regs *wdog = (struct wdog_regs *)WDOG1_BASE_ADDR;
-
-	imx_iomux_v3_setup_multiple_pads(wdog_pads, ARRAY_SIZE(wdog_pads));
-
-	set_wdog_reset(wdog);
-
 	init_uart_clk(2);
 
 	return 0;