Make these structures const as they are only getting passed to the
functions vpfe_{register/unregister}_ccdc_device having the argument as
const.

Structures found using Coccinelle and changes done by hand.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>