"static" on stv06xx for all static functions and parameters to avoid
such troubles.

Cc: Erik Andren <erik.andren@gmail.com>
Cc: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NErik Andren <erik.andren@gmail.com>
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>