drm/i2c: tda998x: change probe message origin

On probe, a message giving the TDA chip version seems to come from the
DRM driver:

	armada-drm armada-510-drm: found TDA19988

This patch changes the originator of the message to the TDA driver:

	tda998x 0-0070: found TDA19988

Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>