MIPS: uasm: add wait instruction

This patch allows use of the wait instruction from uasm. It will be used
by a subsequent patch.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
diff --git a/arch/mips/include/asm/uasm.h b/arch/mips/include/asm/uasm.h
index 306892c..8810801 100644
--- a/arch/mips/include/asm/uasm.h
+++ b/arch/mips/include/asm/uasm.h
@@ -147,6 +147,7 @@
 Ip_0(_tlbr);
 Ip_0(_tlbwi);
 Ip_0(_tlbwr);
+Ip_u1(_wait);
 Ip_u3u1u2(_xor);
 Ip_u2u1u3(_xori);