drm/amdgpu/jpeg2.5: add cancel_delayed_work_sync before power gate

drm/amdgpu/jpeg2.5: add cancel_delayed_work_sync before power gate

BugLink: https://bugs.launchpad.net/bugs/1933691
[ Upstream commit 23f10a571da5eaa63b7845d16e2f49837e841ab9 ]

Add cancel_delayed_work_sync before set power gating state
to avoid race condition issue when power gating.

Signed-off-by: James Zhu <James.Zhu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>