drm/ingenic: Fix MODULE_LICENSE() string

The previous "GPL v2" string is deprecated. For more info, see commit
bf7fbeea ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2" bogosity")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220708205406.96473-3-paul@crapouillou.net

drivers/gpu/drm/ingenic/ingenic-drm-drv.c

@@ -1616,4 +1616,4 @@ module_exit(ingenic_drm_exit);
 
 MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
 MODULE_DESCRIPTION("DRM driver for the Ingenic SoCs\n");
-MODULE_LICENSE("GPL v2");
+MODULE_LICENSE("GPL");