Revert "rtc: Disable the alarm in the hardware"

This reverts commit c0afabd3.

It causes failures on Toshiba laptops - instead of disabling the alarm,
it actually seems to enable it on the affected laptops, resulting in
(for example) the laptop powering on automatically five minutes after
shutdown.

There's a patch for it that appears to work for at least some people,
but it's too late to play around with this, so revert for now and try
again in the next merge window.

See for example

	http://bugs.debian.org/652869



Reported-and-bisected-by: Andreas Friedrich <afrie@gmx.net> (Toshiba Tecra)
Reported-by: Antonio-M. Corbi Bellot <antonio.corbi@ua.es> (Toshiba Portege R500)
Reported-by: Marco Santos <marco.santos@waynext.com> (Toshiba Portege Z830)
Reported-by: Christophe Vu-Brugier <cvubrugier@yahoo.fr>  (Toshiba Portege R830)
Cc: Jonathan Nieder <jrnieder@gmail.com>
Requested-by: John Stultz <john.stultz@linaro.org>
Cc: stable@kernel.org  # for the versions that applied this
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>