drm_hwcomposer: Rename DrmResources to DrmDevice

DrmDevice is a better name to reflect the fact that DrmResources/
DrmDevice can handle just one dri node.

Suggested here [1] by Sean Paul.
[1] https://lists.freedesktop.org/archives/dri-devel/2018-April/173290.html

Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
diff --git a/Android.mk b/Android.mk
index c212127..b8576a5 100644
--- a/Android.mk
+++ b/Android.mk
@@ -56,7 +56,7 @@
 
 LOCAL_SRC_FILES := \
 	autolock.cpp \
-	drmresources.cpp \
+	drmdevice.cpp \
 	drmconnector.cpp \
 	drmcrtc.cpp \
 	drmdisplaycomposition.cpp \