Add common memory fixup function

Add the function fdt_fixup_memory() to fixup the /memory node of the fdt

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/fdt_support.h b/include/fdt_support.h
index 8f781d4..3d6c1a8 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -44,6 +44,7 @@
 			const char *prop, const void *val, int len, int create);
 void do_fixup_by_compat_u32(void *fdt, const char *compat,
 			    const char *prop, u32 val, int create);
+int fdt_fixup_memory(void *blob, u64 start, u64 size);
 void fdt_fixup_ethernet(void *fdt, bd_t *bd);
 
 #ifdef CONFIG_OF_HAS_UBOOT_ENV