V4L/DVB (6180): tuner: don't probe 0x6b or 0x6f on cx88 boards

Ignore 0x6b and 0x6f on cx88 boards. Some FusionHDTV cards
have an ir receiver at 0x6b and an RTC at 0x6f which can
get corrupted if probed.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>