MIPS: uasm: Add mul uasm instruction

It will be used later on by bpf-jit

[ralf@linux-mips.org: Resolved conflict.]

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/6736/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>