sh: Add ashrsi3 libgcc function

The ashrsi3 function is used by some commands that aren't in SH2A
default configs (e.g. JFFS2).

The ashrsi3.S file has been copied from Linux.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/arch/sh/lib/Makefile b/arch/sh/lib/Makefile
index 6aaf55a..256811a 100644
--- a/arch/sh/lib/Makefile
+++ b/arch/sh/lib/Makefile
@@ -28,6 +28,7 @@
 GLSOBJS	+= ashiftlt.o
 GLSOBJS	+= lshiftrt.o
 GLSOBJS	+= ashldi3.o
+GLSOBJS	+= ashrsi3.o
 GLSOBJS	+= lshrdi3.o
 GLSOBJS	+= movmem.o