power: reset: ltc2952: Use hrtimer_forward_now()

hrtimer_forward_now() provides the same functionality as the open coded
hrtimer_forward() invocation. Prepares for removal of hrtimer_forward()
from the public interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>