power: qpnp-smbcharger: ignore battery ov

The smbcharger's battery overvoltage detection cannot be trusted.
Many times, it will trip even though the battery voltage is still well
within safe limits. Because of this, simply ignore the interrupt if it
fires.

CRs-Fixed: 924317
Change-Id: I57decb3a11f6b7bacbe82b0fe69c844f308e890d
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>