drm_hwcomposer: Move include/drmhwcgralloc.h to bufferinfo/BufferInfo.h

... to emphasize its purpose.

- Rename struct HwcDrmBo -> struct BufferInfo
- Remove unused BufferInfo::acquire_fence, BufferInfo::hal_format and
  BufferInfo::usage fields

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/utils/hwcutils.cpp b/utils/hwcutils.cpp
index c537b99..aec9bba 100644
--- a/utils/hwcutils.cpp
+++ b/utils/hwcutils.cpp
@@ -28,7 +28,7 @@
 namespace android {
 
 int DrmHwcLayer::ImportBuffer(DrmDevice *drm_device) {
-  buffer_info = hwc_drm_bo_t{};
+  buffer_info = BufferInfo{};
 
   int ret = BufferInfoGetter::GetInstance()->ConvertBoInfo(sf_handle,
                                                            &buffer_info);