OMAP3: PM: Add milliseconds interface to suspend wakeup timer

Millisecond resolution is possible and there are use cases for it
(automatic testing).

Seconds-based interface is preserved for compatibility.

Signed-off-by: Ari Kauppi <Ext-Ari.Kauppi@nokia.com>
Reviewed-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>