drm/i915: Drop the debug message from vlv_get_fifo_size()

drm/i915: Drop the debug message from vlv_get_fifo_size()

Seeing the display FIFO sizes at driver load time doesn't really provide
anything useful for us, so let's just drop the debug message. One can
always use eg. intel_watermarks to dump out the hardware settings prior
to loading the driver.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170421181432.15216-3-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>