rtc: ds1685: fix ds1685_rtc_alarm_irq_enable build error

The newly added ds1685 driver causes a build error when enabled without
CONFIG_RTC_INTF_DEV:

  drivers/rtc/rtc-ds1685.c:919:22: error: 'ds1685_rtc_alarm_irq_enable' undeclared here (not in a function)
    .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,

Apparently the driver was incorrectly changed to reflect the interface
change from 16380c15 ("RTC: Convert rtc drivers to use the
alarm_irq_enable method"), which removed the respective #ifdef from all
other rtc drivers.

This does the same change that was merged for the other drivers before and
removes the #ifdef, allowing the interrupts to be enabled through the
in-kernel rtc interface independent of the existence of /dev/rtc.

Fixes: aaaf5fbf

 ("rtc: add driver for DS1685 family of real time clocks")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>