Correct QAM symbol_rate_min for lgdt3302 and lgdt3303

Thanks to: Mac Michaels and Steve Malenfant
Signed-off-by: Mac Michaels <wmichaels1@earthlink.net>
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>