drm/i915/lmem: use new struct drm_device based logging macros.

Replace instances of printk based logging macros with the new
struct drm_device logging macros in i915/intel_region_lmem.c.

Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7f3df2575ab41a052b7beea86ecc5385edf6f6da.1578409433.git.wambui.karugax@gmail.com