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>

arch/arm/mach-omap2/pm-debug.c

@@ -548,6 +548,9 @@ static int option_set(void *data, u64 val)
 {
 	u32 *option = data;
 
+	if (option == &wakeup_timer_milliseconds && val >= 1000)
+		return -EINVAL;
+
 	*option = val;
 
 	if (option == &enable_off_mode)