cx25821: use pci_set_dma_mask insted of pci_dma_supported

This ensures the dma mask that is supported by the driver is recorded
in the device structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>