powerpc/mm: Move out definition of CPU specific is_write bits

Define a common page_fault_is_write() helper and use it

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Benjamin Herrenschmidt 2017-07-19 14:49:29 +10:00 • committed by Michael Ellerman
commit 41b464e5e5