MIPS: Barrier: Add definitions of SYNC stype values

Add the definitions of sync stype 0 (global completion barrier) and sync
stype 0x10 (local ordering barrier) to barrier.h for use with the sync
instruction.

These types are defined by the MIPS Instruction Set since R2 of the
architecture and are documented in document MD00087 table 6.5.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14222/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>