power management: change /sys/power/disk display

power management: change /sys/power/disk display

Change /sys/power/disk to display all valid modes as well as the currently
selected one in a fashion known from the LED subsystem.

This changes userspace API, but it is apparently not used much (we asked
some userspace developers)

Signed-off-by: Johannes Berg <[email protected]>
Acked-by: "Rafael J. Wysocki" <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>