[media] au8522: don't touch i2c master registers on au8522

Some stray lines got inserted into the driver when I reverse engineered
the I2C traffic (at the time I didn't know what the registers did).

It turns up these registers muck with the onboard I2C master, which
we don't use since we instead use the I2C gate.  Remove the lines
which can actually interfere with the operation of the bus.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>