drm/amdgpu/display: these forward declarations are not used

Remove them.

Signed-off-by: ZhiJie.Zhang <zhangzhijie@loongson.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
ZhiJie.Zhang 2021-01-15 11:41:52 +08:00 • committed by Alex Deucher
commit f4fb559531