ozone/drm: Use uint64_t for the DrmProperty::value member variable

Update the 'value' member variable of the DrmProperty class to be a uint64_t
since this is the type expected by the DRM APIs.

Bug: None
Test: Chrome on Ozone-DRM
Change-Id: I51fe25d1d70e0ffbeda72312b8910c1dd8d41527
Reviewed-on: https://chromium-review.googlesource.com/1091317Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Daniel Nicoara <dnicoara@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565655}

ui/ozone/platform/drm/gpu/drm_device.h

@@ -68,7 +68,7 @@ class DrmDevice : public GbmDeviceLinux,
 
     // Depending on the property, this may be an actual value describing the
     // property or an ID of another property.
-    uint32_t value;
+    uint64_t value;
   };
 
   DrmDevice(const base::FilePath& device_path,