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/platform.cpp b/platform.cpp
index b6c39d0..39761fa 100644
--- a/platform.cpp
+++ b/platform.cpp
@@ -16,7 +16,7 @@
 
 #define LOG_TAG "hwc-platform"
 
-#include "drmresources.h"
+#include "drmdevice.h"
 #include "platform.h"
 
 #include <log/log.h>