drm/amdgpu: Use dpm_enabled as dpm state flag

driver will set dpm_enabled to true only when
module parameter amdgpu_dpm not equal to 0 and
smu hw initialize successfully.

Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Huang Rui <ray.huang@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/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 448d69f..c98e597 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -428,7 +428,7 @@ static ssize_t amdgpu_debugfs_sensor_read(struct file *f, char __user *buf,
 	if (size & 3 || *pos & 0x3)
 		return -EINVAL;
 
-	if (amdgpu_dpm == 0)
+	if (!adev->pm.dpm_enabled)
 		return -EINVAL;
 
 	/* convert offset to sensor number */