[PATCH] dvb: nxt6000: support frontend status reads

add support for read_ber, read_signal_strength and read_status (Greg Wickham)

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>