arm: added architecture-specific implementation of __cr_restore_rt

Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/arm/syscall-common.S

@@ -50,3 +50,7 @@
         bx      %lr
         END(\name)
         .endm
+
+ENTRY(__cr_restore_rt)
+	do_sys __NR_rt_sigreturn
+END(__cr_restore_rt)