Build set and clear macros for the PageGrain register.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9289/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>