MIPS: pm-cps: Remove selection of sync types

Instead of selecting an implementation or vendor specific sync type for
the required sync operations, always use the architecturally mandated
sync types which previous patches have put in place. The selection of
special sync types is now redundant an can be removed.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14223/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>