[media] az6007: handle CI during suspend/resume

The dvb-usb-v2 core doesn't know anything about CI. So, the
driver needs to handle it by hand. This patch stops CI just
before stopping URB's/RC, and restarts it before URB/RC start.

It should be noticed that suspend/resume is not yet working properly,
as the PM model requires the implementation of reset_resume:
	dvb_usb_az6007 1-6:1.0: no reset_resume for driver dvb_usb_az6007?
But this is not implemented there at dvb-usb-v2 yet.

Cc: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>