V4L/DVB (8492): Add support for the ATI TV Wonder HD 600

em28xx-cards.c
em28xx-dvb.c
em28xx.h
 - Add support for the ATI TV Wonder HD 600, based on a 94 email exchange and
   USB traces provided by Ronnie Bailey

   Thanks to Ronnie Bailey <purevw@wtxs.net> for testing the changes

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>