drm_hwcomposer: Tidy-up DrmDevice class

1. Move drm/DrmConnector.h to Normal clang-tidy checks list by fixing
   clang-tidy findings.

2. Remove DrmDevice self-reference.

3. Replace shared_ptr reference to DrmDevice in DrmFbImporter with a
   pointer, making ResourceManager only owner of DrmDevice and its
   chilren.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/compositor/DrmDisplayCompositor.cpp b/compositor/DrmDisplayCompositor.cpp
index c2db7fc..d25fb98 100644
--- a/compositor/DrmDisplayCompositor.cpp
+++ b/compositor/DrmDisplayCompositor.cpp
@@ -178,7 +178,7 @@
   if (args.test_only)
     flags |= DRM_MODE_ATOMIC_TEST_ONLY;
 
-  int err = drmModeAtomicCommit(drm->fd(), pset.get(), flags, drm);
+  int err = drmModeAtomicCommit(drm->GetFd(), pset.get(), flags, drm);
   if (err) {
     if (!args.test_only)
       ALOGE("Failed to commit pset ret=%d\n", err);
@@ -230,7 +230,7 @@
   }
 
   if (connector->GetDpmsProperty()) {
-    drmModeConnectorSetProperty(drm->fd(), connector->GetId(),
+    drmModeConnectorSetProperty(drm->GetFd(), connector->GetId(),
                                 connector->GetDpmsProperty().id(),
                                 DRM_MODE_DPMS_ON);
   }