V4L/DVB: smsir: make local variables static

Make the file local parameters static.

This will remove the following sparse warnings (see "make C=1"):
 * warning: symbol 'ir_pos' was not declared. Should it be static?
 * warning: symbol 'ir_word' was not declared. Should it be static?
 * warning: symbol 'ir_toggle' was not declared. Should it be static?

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>