drivers/rtc/rtc-m41t80.c: remove disabled alarm functionality

Commit c3b79770

 ("rtc: m41t80: Workaround broken alarm
functionality") disabled m41t80's alarm functions.  But since those
functions were not touched, building this driver triggers these GCC
warnings:

    drivers/rtc/rtc-m41t80.c:216:12: warning: 'm41t80_rtc_alarm_irq_enable' defined but not used [-Wunused-function]
    drivers/rtc/rtc-m41t80.c:238:12: warning: 'm41t80_rtc_set_alarm' defined but not used [-Wunused-function]
    drivers/rtc/rtc-m41t80.c:308:12: warning: 'm41t80_rtc_read_alarm' defined but not used [-Wunused-function]

Remove these functions (and the commented out references to them) to
silence these warnings.  Anyone wanting to fix the alarm irq functionality
can easily find the removed code in the git log of this file or through
some web searches.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>