[media] stv0367: get rid of warning: no previous prototype

drivers/media/dvb-frontends/stv0367.c:1267:25: warning: no previous prototype for 'stv0367ter_lock_algo' [-Wmissing-prototypes]
drivers/media/dvb-frontends/stv0367.c:1531:5: warning: no previous prototype for 'stv0367ter_init' [-Wmissing-prototypes]
drivers/media/dvb-frontends/stv0367.c:2381:21: warning: no previous prototype for 'stv0367cab_SetQamSize' [-Wmissing-prototypes]
drivers/media/dvb-frontends/stv0367.c:2765:5: warning: no previous prototype for 'stv0367cab_init' [-Wmissing-prototypes]
drivers/media/dvb-frontends/stv0367.c:882:4: warning: no previous prototype for 'stv0367_getbits' [-Wmissing-prototypes]

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