Ensure that the twd timer reload value is reprogrammed each time we
enter periodic mode.  This ensures that the reload value is always
reset correctly.
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NColin Cross <ccross@android.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>