[media] az6007: Fix the I2C code in order to handle mt2063

mt2063 uses a one-byte transfer. This requires a special handling
inside the i2c code. Fix it to properly accept i2c reads. This
is needed to make the mt2063 to be detected.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>