Revert "drm/amdgpu: disable runtime pm on PX laptops without dGPU power control"

This reverts commit bedf2a65c1aa8fb29ba8527fd00c0f68ec1f55f1.

See the radeon revert for an extended description.

Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 61211747..2139da7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -62,12 +62,6 @@
 	"LAST",
 };
 
-#if defined(CONFIG_VGA_SWITCHEROO)
-bool amdgpu_has_atpx_dgpu_power_cntl(void);
-#else
-static inline bool amdgpu_has_atpx_dgpu_power_cntl(void) { return false; }
-#endif
-
 bool amdgpu_device_is_px(struct drm_device *dev)
 {
 	struct amdgpu_device *adev = dev->dev_private;
@@ -1485,7 +1479,7 @@
 
 	if (amdgpu_runtime_pm == 1)
 		runtime = true;
-	if (amdgpu_device_is_px(ddev) && amdgpu_has_atpx_dgpu_power_cntl())
+	if (amdgpu_device_is_px(ddev))
 		runtime = true;
 	vga_switcheroo_register_client(adev->pdev, &amdgpu_switcheroo_ops, runtime);
 	if (runtime)