V4L/DVB (13808b): mantis: replace DMA_nnBIT_MASK to DMA_BIT_MASK(32)

drivers/media/dvb/mantis/mantis_pci.c: In function ‘mantis_pci_init’:
drivers/media/dvb/mantis/mantis_pci.c:76: warning: ‘DMA_nnBIT_MASK’ is deprecated

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>