rtc: cros-ec: Make license text and module license match.

The license text is specifying "GPLv2" but the MODULE_LICENSE is set to
GPL which means GNU Public License v2 or later. When MODULE_LICENSE and
boiler plate does not match, go for boiler plate license.
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-cros-ec.c

@@ -409,5 +409,5 @@ module_platform_driver(cros_ec_rtc_driver);
 
 MODULE_DESCRIPTION("RTC driver for Chrome OS ECs");
 MODULE_AUTHOR("Stephen Barber <smbarber@chromium.org>");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:" DRV_NAME);