ARM: dts: am43xx: Update spl specific dts

Now that we can specify DT nodes that can be used in spl, mark
all necessary nodes as u-boot,dm-spl.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/dts/am437x-gp-evm-u-boot.dtsi

@@ -9,30 +9,30 @@
 
 /{
 	ocp {
-		u-boot,dm-pre-reloc;
+		u-boot,dm-spl;
 	};
 };
 
 &uart0 {
-	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
 };
 
 &mmc1 {
-	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
 };
 
 &mac {
-	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
 };
 
 &davinci_mdio {
-	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
 };
 
 &cpsw_emac0 {
-	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
 };
 
 &phy_sel {
-	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
 };