FROMLIST: virt: geniezone: Emulate IPI for guest VM

Emulate Inter-Processor Interrupts (IPI) handling for guest VMs.
Ensure that when a vCPU thread enters an idle state and relinquishes
CPU control to the host, it can be woken up by IPIs issued by other
vCPUs through the gzvm driver.

Add a new wake-up mechanism, `GZVM_EXIT_IPI`, to handle IPIs. Ensure
that idle vCPUs can be woken up not only by virtual timer (vtimer) and
virtio interrupts but also by IPIs issued by other vCPUs.

Ensure proper handling of IPIs, allowing idle vCPUs to be woken up and
respond to interrupts, thereby maintaining correct and efficient
inter-processor communication within the guest VM.

Change-Id: Ic3414646d5439288f9592cdc1d74f46a552a1a5a
Signed-off-by: Kevenny Hsieh <kevenny.hsieh@mediatek.com>
Signed-off-by: Liju Chen <liju-clr.chen@mediatek.com>
Bug: 356552547
Link: https://lore.kernel.org/lkml/20240730082436.9151-25-liju-clr.chen@mediatek.com/