arm: dts: k3-j721e-common-proc-board: Add pinmux for SD card

Add pinmux for sdhci1 node connected to the SD card.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/arch/arm/dts/k3-j721e-common-proc-board-u-boot.dtsi b/arch/arm/dts/k3-j721e-common-proc-board-u-boot.dtsi
index 9ca025c..aff0efa 100644
--- a/arch/arm/dts/k3-j721e-common-proc-board-u-boot.dtsi
+++ b/arch/arm/dts/k3-j721e-common-proc-board-u-boot.dtsi
@@ -325,3 +325,7 @@
 		reg-names = "gmii-sel";
 	};
 };
+
+&main_mmc1_pins_default {
+	u-boot,dm-spl;
+};