page_pool: Set `dma_sync` to false for devmem memory provider

Move the `dma_map` and `dma_sync` checks to `page_pool_init` to make
them generic. Set dma_sync to false for devmem memory provider because
the dma_sync APIs should not be used for dma_buf backed devmem memory
provider.

Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20241211212033.1684197-4-almasrymina@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>