commit 5f1b2f77 upstream.

Fix RTC write bit as per application manual
Signed-off-by: Mitja Spes <mitja@lxnav.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>