- Fixed issue with hotplugging and DMA sound (sound was lost when replugging
  a card)

- Added notifiers to main saa7134 module to let the sound sub-modules know
  when a card has been inserted or removed
Signed-off-by: NRicardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>