fix irq flags in rtc-ds1511

The file in drivers/rtc/rtc-ds1551.c uses "int" for flags.  This can cause
hard to find bugs on some architectures.  This patch converts the flags to use
"long" instead.

This bug was discovered by doing an allyesconfig make on the -rt kernel where
checks are done to ensure all flags are of size sizeof(long).

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>