MIPS: Handle microMIPS jumps in the same way as MIPS32/MIPS64 jumps

is_jump_ins() checks for plain jump ("j") instructions since commit
e7438c4b ("MIPS: Fix sibling call handling in get_frame_info") but
that commit didn't make the same change to the microMIPS code, leaving
it inconsistent with the MIPS32/MIPS64 code. Handle the microMIPS
encoding of the jump instruction too such that it behaves consistently.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: e7438c4b ("MIPS: Fix sibling call handling in get_frame_info")
Cc: Tony Wu <tung7970@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # v3.10+
Patchwork: https://patchwork.linux-mips.org/patch/14533/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/process.c

@@ -294,6 +294,8 @@ static inline int is_jump_ins(union mips_instruction *ip)
 		return 0;
 	}
 
+	if (ip->j_format.opcode == mm_j32_op)
+		return 1;
 	if (ip->j_format.opcode == mm_jal32_op)
 		return 1;
 	if (ip->r_format.opcode != mm_pool32a_op ||