soc: mediatek: Move the initial setting of pmic wrap interrupt before requesting irq.

The watchdog may not be initialized by the bootloader, even if the rest
of the pwrap is. Move the watchdog initialization out of pwrap_init() to
make sure the watchdog is always initialized and not only when the pwrap
is uninitialized.

Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>