drm/i915/display: Add debug print for scaler filter

Add debug print statement to print scaler filter property
value. Since property can be set as either default or integer
scaler; its good if we can get debug print for the same in dmesg
log.

Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220706102240.21414-1-swati2.sharma@intel.com