This patch adds the sysfs interface to the RTC subsystem.

Each RTC client will have his own entry under /sys/classs/rtc/rtcN .

Within this entry some attributes are exported by the subsystem, like date and
time.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>