rtc: make class.c explicitly non-modular

The Makefile/Kconfig currently controlling compilation of this code is:

obj-$(CONFIG_RTC_CLASS)         += rtc-core.o
rtc-core-y                      := class.o interface.o

drivers/rtc/Kconfig:menuconfig RTC_CLASS
drivers/rtc/Kconfig:    bool "Real Time Clock"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the code there is no doubt it is builtin-only.

We don't replace module.h with init.h since the file does need
to know what a struct module is.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/class.c

@@ -361,17 +361,4 @@ static int __init rtc_init(void)
 	rtc_dev_init();
 	return 0;
 }
-
-static void __exit rtc_exit(void)
-{
-	rtc_dev_exit();
-	class_destroy(rtc_class);
-	ida_destroy(&rtc_ida);
-}
-
 subsys_initcall(rtc_init);
-module_exit(rtc_exit);
-
-MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
-MODULE_DESCRIPTION("RTC class support");
-MODULE_LICENSE("GPL");