drm/amd/display: [FW Promotion] Release 1.0.15

[Header Changes]
- Add new initialization bits for driver to check
  firmware status
- Add command for HW locking via DMUB

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>