reset: berlin: drop arch_initcall initialization

With proper platform driver probing for berlin reset driver, drop the
arch_initcall workaround.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>