[media] smiapp: Pass struct sensor to register writing commands instead of i2c_client

Pass struct sensor to register access commands. This allows taking quirks
into account in register access.

Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>