This reverts commit 072030b1.
This is no longer necessary when using newer DMUB F/W.

Cc: stable@vger.kernel.org
Cc: Sean Wang <sean.ns.wang@amd.com>
Cc: Marc Rossi <Marc.Rossi@amd.com>
Cc: Hamza Mahfooz <Hamza.Mahfooz@amd.com>
Cc: Tsung-hua (Ryan) Lin <Tsung-hua.Lin@amd.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>