drm/i915: Make scaler updates less chatty

It looks to me skl_update_scaler will already log interesting
debug messages when the state transitions or there is an error.

In this case it feels we can remove the two unconditional
debug messages which happen immediately before calling
skl_update_scaler. This way we get rid of the sole debug
message when switching virtual terminals for example.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479376805-5087-1-git-send-email-tvrtko.ursulin@linux.intel.com