feat(fwu): introduce FWU platform-specific functions declarations

Added FWU platform specific functions declarations in common
platform header.

Change-Id: I637e61753ea3dc7f7e7f3159ae1b43ab6780aef2
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

include/plat/common/platform.h

@@ -16,6 +16,7 @@
 #if TRNG_SUPPORT
 #include "plat_trng.h"
 #endif
+#include <drivers/fwu/fwu_metadata.h>
 
 /*******************************************************************************
  * Forward declarations
@@ -349,4 +350,12 @@ int32_t plat_get_soc_revision(void);
  */
 int32_t plat_is_smccc_feature_available(u_register_t fid);
 
+/*******************************************************************************
+ * FWU platform specific functions
+ ******************************************************************************/
+int plat_fwu_set_metadata_image_source(unsigned int image_id,
+				       uintptr_t *dev_handle,
+				       uintptr_t *image_spec);
+void plat_fwu_set_images_source(struct fwu_metadata *metadata);
+
 #endif /* PLATFORM_H */