V4L/DVB (5050): Pvrusb2: Newer frequency range checking

Implement new method for doing integer range checking, so that we can
more intelligently range-check radio and tv ranges at once.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>