[ARM] 3898/1: corgi_bl fix module loading

Fix module loading:
corgi_bl: module license 'GPLv2' taints kernel.
corgi_bl: Unknown symbol platform_driver_unregister
corgi_bl: Unknown symbol __symbol_get
corgi_bl: Unknown symbol platform_driver_register

Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NpHilipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: NAnton Vorontsov <cbou@mail.ru>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

drivers/video/backlight/corgi_bl.c

@@ -166,4 +166,4 @@ module_exit(corgibl_exit);
 
 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
 MODULE_DESCRIPTION("Corgi Backlight Driver");
-MODULE_LICENSE("GPLv2");
+MODULE_LICENSE("GPL");