media: dvb-frontends/lnbh25: improve kernellog output

Use dev_dbg() in conjunction with the %*ph format macro to print the vmon
status debug, thus hiding continuous hexdumping from default log levels.
Also, change the attach success log line from error to info severity.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Acked-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>