omap1/pm.c build fix

Build fix:

arch/arm/mach-omap1/pm.c: In function 'omap_pm_init':
arch/arm/mach-omap1/pm.c:720: warning: passing argument 2 of 'sysfs_create_file' from incompatible pointer type

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>