nios2: implement the new page table range API

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

Link: https://lkml.kernel.org/r/20230802151406.3735276-19-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>