[media] tvp5150: device detection should be done only once

Having the device detection happening at reset is bad, as every time,
it will produce a message like:
	tvp5150 2-005c: tvp5150am1 detected.

This only polutes the log and for an accidental kernel hacker, it looks
like a real problem. So, move those printk's to happen during device
probe.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>