drm/amdgpu: Fix kernel NULL pointer dereference in dpm functions

caused by
'commit 83e3c4615872 ("drm/amdgpu: Remove wrapper layer of smu ip functions")'

BUG: unable to handle kernel NULL pointer dereference at 00000000000005d8
[  313.241459] IP: ci_dpm_read_sensor+0x37/0xf0 [amdgpu]

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/ci_dpm.c b/drivers/gpu/drm/amd/amdgpu/ci_dpm.c
index 98d1dd2..47ef3e6 100644
--- a/drivers/gpu/drm/amd/amdgpu/ci_dpm.c
+++ b/drivers/gpu/drm/amd/amdgpu/ci_dpm.c
@@ -6244,6 +6244,7 @@ static int ci_dpm_early_init(void *handle)
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
 	adev->powerplay.pp_funcs = &ci_dpm_funcs;
+	adev->powerplay.pp_handle = adev;
 	ci_dpm_set_irq_funcs(adev);
 
 	return 0;