powerpc/mm: Move around mmu_gathers definition on 64-bit

The definition for the global structure mmu_gathers, used by generic code,
is currently defined in multiple places not including anything used by
64-bit Book3E. This changes it by moving to one place common to all
processors.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
3 files changed