Blackfin arch: add proper ENDPROC()

add proper ENDPROC() to close out assembly functions
so size/type is set properly in the final ELF image

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/arch/blackfin/lib/memset.S b/arch/blackfin/lib/memset.S
index ba6d047..8159136 100644
--- a/arch/blackfin/lib/memset.S
+++ b/arch/blackfin/lib/memset.S
@@ -106,4 +106,4 @@
 	B[P0++] = R1;
 	JUMP .Laligned;
 
-.size _memset,.-_memset
+ENDPROC(_memset)