powerpc: implement the new page table range API

powerpc: implement the new page table range API

Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio().  Change
the PG_arch_1 (aka PG_dcache_dirty) flag from being per-page to per-folio.

[[email protected]: re-export flush_dcache_icache_folio()]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Acked-by: Mike Rapoport (IBM) <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>