Acpica gpe

Some GPE divergence reduction and fixes.

1. Events: Fix a divergence that OriginallyEnabled check is not paired.
    This is a divergence fix.
2. Events: Fix edge-triggered GPE by disabling before acknowledging it.
    This is a fix that is generated according to the ACPI spec. Tests showed valid.
3. Events: Add unconditional GPE enabling support.
    The AcpiSetGpe() API has actually no user now. The improvement could facilitate driver writers to use this API to implement GPE handling flexibilities.
4. Events: Add a flag to disable internal auto GPE clearing.
    Another commit to facilitates driver writers to implement GPE handling flexibilities.