[media] stv0367: fix sparse warnings

drivers/media/dvb-frontends/stv0367.c:557:5: warning: symbol 'stv0367cab_RF_LookUp1' was not declared. Should it be static?
drivers/media/dvb-frontends/stv0367.c:569:5: warning: symbol 'stv0367cab_RF_LookUp2' was not declared. Should it be static?

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>