MIPS: Add TLBR and ROTR to uasm.

The soon to follow Read Inhibit/eXecute Inhibit patch needs TLBR and
ROTR support in uasm.  We also add a UASM_i_ROTR macro.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/953/


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