drm_hwcomposer: rename file with underscore to not use underscore

Change-Id: Icbaef79cb224b45e500ac3a0e3f987de24151d6a
diff --git a/drm_hwcomposer.h b/drmhwcomposer.h
similarity index 100%
rename from drm_hwcomposer.h
rename to drmhwcomposer.h