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/memmove.S b/arch/blackfin/lib/memmove.S
index 2e5fb7f..c371585 100644
--- a/arch/blackfin/lib/memmove.S
+++ b/arch/blackfin/lib/memmove.S
@@ -100,4 +100,4 @@
 	P3 = I1;
 	RTS;
 
-.size _memmove,.-_memmove
+ENDPROC(_memmove)