drm/i2c: tda998x: increase the supported dotclock frequency to 165MHz for TDA19988

Spec sheet states that the TDA19988 supports up to 165MHz dotclock
speeds. Without this change modes higher than 1080p are un-attainable.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>