drm/amd/display: Disable SYMCLK32_LE root clock gating

drm/amd/display: Disable SYMCLK32_LE root clock gating

[WHY & HOW]
On display on sequence, enabling SYMCLK32_LE root clock gating
causes issue in link training so disabling it is needed.

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Sung Joon Kim <Sungjoon.Kim@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>