mm: ioremap: Add ioremap/iounmap_allowed()

mm: ioremap: Add ioremap/iounmap_allowed()

Add special hook for architecture to verify addr, size or prot
when ioremap() or iounmap(), which will make the generic ioremap
more useful.

  ioremap_allowed() return a bool,
    - true means continue to remap
    - false means skip remap and return directly
  iounmap_allowed() return a bool,
    - true means continue to vunmap
    - false code means skip vunmap and return directly

Meanwhile, only vunmap the address when it is in vmalloc area
as the generic ioremap only returns vmalloc addresses.

Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20220607125027.44946-5-wangkefeng.wang@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>