vgaswitcheroo: add vga_switcheroo_fini_domain_pm_ops

Drivers should call this on unload to unregister pmops.

Bug:
https://bugzilla.kernel.org/show_bug.cgi?id=84431

Reviewed-by: Ben Skeggs <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
Cc: [e-mail]
Signed-off-by: Pali Rohár <[e-mail]>
Cc: Ben Skeggs <[e-mail]>

drivers/gpu/vga/vga_switcheroo.c

···
 }
 EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_ops);
 
+void vga_switcheroo_fini_domain_pm_ops(struct device *dev)
+{
+	dev->pm_domain = NULL;
+}
+EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops);
+
 static int vga_switcheroo_runtime_resume_hdmi_audio(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);

include/linux/vga_switcheroo.h

···
 void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic);
 
 int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain);
+void vga_switcheroo_fini_domain_pm_ops(struct device *dev);
 int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, struct dev_pm_domain *domain);
 #else
 
···
 static inline void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, enum vga_switcheroo_state dynamic) {}
 
 static inline int vga_switcheroo_init_domain_pm_ops(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }
+static inline void vga_switcheroo_fini_domain_pm_ops(struct device *dev) {}
 static inline int vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev, struct dev_pm_domain *domain) { return -EINVAL; }
 
 #endif