[PATCH] remove kernel/power/pm.c:pm_unregister()

Since the last user is removed in -mm, we can now remove this long deprecated
function.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>