drm/amd/pm: use pm_runtime_resume_and_get

Using pm_runtime_resume_and_get over pm_runtime_get_sync is recommended.

Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>