drm/amd/pm: resolve reboot exception for si oland

commit e490d60a

 upstream.

During reboot test on arm64 platform, it may failure on boot.

The error message are as follows:
[    1.706570][ 3] [  T273] [drm:si_thermal_enable_alert [amdgpu]] *ERROR* Could not enable thermal interrupts.
[    1.716547][ 3] [  T273] [drm:amdgpu_device_ip_late_init [amdgpu]] *ERROR* late_init of IP block <si_dpm> failed -22
[    1.727064][ 3] [  T273] amdgpu 0000:02:00.0: amdgpu_device_ip_late_init failed
[    1.734367][ 3] [  T273] amdgpu 0000:02:00.0: Fatal error during GPU init

v2: squash in built warning fix (Alex)

Signed-off-by: Zhenneng Li <lizhenneng@kylinos.cn>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>