platform/x86: intel_crystal_cove_charger: Fix IRQ masking / unmasking

The driver as originally submitted accidentally relied on Android having
run before and Android having unmasked the 2nd level IRQ-mask for the
charger IRQ. This worked since these are PMIC registers which are only
reset when the battery is fully drained or disconnected.

Fix the charger IRQ no longer working after loss of battery power by
properly setting the 2nd level IRQ-mask for the charger IRQ.

Note this removes the need to enable/disable our parent IRQ which just
sets the mask bit in the 1st level IRQ-mask register, setting one of
the 2 level masks is enough to stop the IRQ from getting reported.

Fixes: 761db353d9e2 ("platform/x86: Add intel_crystal_cove_charger driver")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220111232309.377642-1-hdegoede@redhat.com

platform/x86: Add intel_crystal_cove_charger driver

Driver for the external-charger IRQ pass-through function of the
Intel Bay Trail Crystal Cove PMIC.

Note this is NOT a power_supply class driver, it just deals with IRQ
pass-through, this requires this separate driver because the PMIC's
level 2 interrupt for this must be explicitly acked.

This new driver gets enabled by the existing X86_ANDROID_TABLETS Kconfig
option because the x86-android-tablets module is the only consumer of the
exported external-charger IRQ.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211225115509.94891-5-hdegoede@redhat.com