arm: Add support of updating dts before fix-up

"ethernet" node fix-up for device tree happens before Linux boot.

There can be requirement of updating "ethernet" node even before
fix-up. So, add support of updating "ethernet" node.

Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>

arch/arm/lib/bootm-fdt.c

@@ -25,6 +25,13 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#ifdef CONFIG_FMAN_ENET
+__weak int fdt_update_ethernet_dt(void *blob)
+{
+	return 0;
+}
+#endif
+
 int arch_fixup_fdt(void *blob)
 {
 	int ret = 0;
@@ -64,5 +71,10 @@ int arch_fixup_fdt(void *blob)
 #endif
 #endif
 
+#ifdef CONFIG_FMAN_ENET
+	ret = fdt_update_ethernet_dt(blob);
+	if (ret)
+		return ret;
+#endif
 	return 0;
 }