drm/amd/display: Temporarily disable clock gating

Temporarily disable dchubbub clock gating, registers:
.DISPCLK_R_DCHUBBUB_GATE_DIS
.DCFCLK_R_DCHUBBUB_GATE_DIS

need to follow up with sequence issue.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Leo Chen <sanchuan.chen@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>