drm/amd/powerplay: check whether enable dpm in powerplay.

BugLink: http://bugs.launchpad.net/bugs/1546572

Change-Id: I0a2dbf8ef7d4a3e9788fe211fc5964dd2487c519
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
(cherry picked from commit 1ea6c1e8)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_powerplay.c

@@ -144,8 +144,11 @@ static int amdgpu_pp_sw_init(void *handle)
 
 #ifdef CONFIG_DRM_AMD_POWERPLAY
 	if (adev->pp_enabled) {
-		adev->pm.dpm_enabled = true;
 		amdgpu_pm_sysfs_init(adev);
+		if (amdgpu_dpm == 0)
+			adev->pm.dpm_enabled = false;
+		else
+			adev->pm.dpm_enabled = true;
 	}
 #endif