[media] m88rs2000: add caps FE_CAN_INVERSION_AUTO

The m88rs2000 frontend is always auto inversion.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>