[media] au8522: set signal field to 100% when signal present

The signal state field in G_TUNER is typically scaled from 0-100%. Since we
don't know the signal level, we really would prefer the field to contain 100%
than 1/256, which in many utilities (such as v4l2-ctl) rounds to 0% even when
a signal is actually present.

This patch makes the behavior consistent with other drivers.

Signed-off-by: Devin Heitmueller <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/dvb/frontends/au8522_decoder.c

···
 	/* Interrogate the decoder to see if we are getting a real signal */
 	lock_status = au8522_readreg(state, 0x00);
 	if (lock_status == 0xa2)
-		vt->signal = 0x01;
+		vt->signal = 0xffff;
 	else
 		vt->signal = 0x00;