[media] media: dvb-core: Don't force CAN_INVERSION_AUTO in oneshot mode

When in FE_TUNE_MODE_ONESHOT the frontend must report
the actual capabilities so user can take appropriate
action.

With frontends that can't do auto inversion this is done
by dvb-core automatically so CAN_INVERSION_AUTO is valid.

However, when in FE_TUNE_MODE_ONESHOT this is not true.

So only set FE_CAN_INVERSION_AUTO in modes other than
FE_TUNE_MODE_ONESHOT

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>