V4L/DVB (13033): pt1: Don't use a deprecated DMA_BIT_MASK macro

drivers/media/dvb/pt1/pt1.c: In function ‘pt1_probe’:
drivers/media/dvb/pt1/pt1.c:915: warning: ‘DMA_nnBIT_MASK’ is deprecated

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