[media] au0828: break au0828_card_setup() down into smaller functions

Pull the analog frontend setup code out of au0828_card_setup into its
own seperate function, au0828_card_analog_fe_setup().

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>