ARM: vITS: handle INV command

ARM: vITS: handle INV command

The INV command instructs the ITS to update the configuration data for
a given LPI by re-reading its entry from the property table.
We don't need to care so much about the priority value, but enabling
or disabling an LPI has some effect: We remove or push virtual LPIs
to their VCPUs, also check the virtual pending bit if an LPI gets enabled.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>