[media] Staging: media: radio-bcm2048: Remove FSF address from GPL notice

Removes the superfluous statement about writing to the FSF in the GPL
notice

Signed-off-by: Jean-Baptiste Abbadie <jb@abbadie.fr>
Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>