driver: intc: npcx: remove 'interrupt disable' in miwu configure func.

In this CL, npcx_miwu_interrupt_configure is no longer responsible for
turning the interrupt off. Although the default state of WK_EN is
disabled, the users still have the chance to configure them when WK_EN
is enabled via npcx_miwu_irq_enable(). Hence, this CL also ensures that
WK_EN is disabled before configuring them.

Signed-off-by: Mulin Chao <mlchao@nuvoton.com>