V4L/DVB (8465): cx23885: Ensure PAD_CTRL is always reset to a sensible default

PAD_CTRL controls TS1 and TS2 input and output states, if the register
became corrupt the driver was never able to recover.

Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>