V4L/DVB (13013): FM TX: si4713: Kconfig: Fixed two typos.

Fixed two typos.

Signed-off-by: Matti J. Aaltonen <matti.j.aaltonen@nokia.com>
Acked-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>