platform/x86: wmi: add context pointer field to struct wmi_device_id

When using wmi_install_notify_handler() to initialize a WMI handler a
data pointer can be supplied which will be passed on to the notification
handler. No similar feature exist when handling WMI events via struct
wmi_driver.

Add a context field pointer to struct wmi_device_id and add a function
find_guid_context() to retrieve that context pointer.

Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

include/linux/mod_devicetable.h

@@ -798,6 +798,7 @@ struct tee_client_device_id {
  */
 struct wmi_device_id {
 	const char guid_string[UUID_STRING_LEN+1];
+	const void *context;
 };
 
 #endif /* LINUX_MOD_DEVICETABLE_H */