it8xxx2/espi: disable IBF interrupt by calling interrupt controller API

Disable input buffer full interrupt for 60h/64h and 62h/66 ports by
calling interrupt controller API. The API has barrier mechanism to
ensure that a thread's requirement to disable peripheral interrupt
takes effect before enabling CPU interrupt. Therefore, the disabling
operation does not occur in ISR and results in interrupt 0 symptom.

Signed-off-by: Dino Li <Dino.Li@ite.com.tw>