microblaze: Adding likely macros

On the base on GCOV analytics is helpful to add likely/unlikely
macros.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/lib/memcpy.c b/arch/microblaze/lib/memcpy.c
index cc2108b..014bac9 100644
--- a/arch/microblaze/lib/memcpy.c
+++ b/arch/microblaze/lib/memcpy.c
@@ -53,7 +53,7 @@
 	const uint32_t *i_src;
 	uint32_t *i_dst;
 
-	if (c >= 4) {
+	if (likely(c >= 4)) {
 		unsigned  value, buf_hold;
 
 		/* Align the dstination to a word boundry. */