[media] dib8000: improve debug messages

When debug is enabled:
	- Report when frontend gets restarted;
	- Be coherent on the displayed lines;
	- Show the transmission mode;
	- Hide unused layers.

No functional changes (except at the printk's).

Acked-By: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>