ANDROID: KVM: arm64: s2mpu: Add SysMMU_SYNC timeout

The SysMMU_SYNC provides an invalidation-complete signal to the
hypervisor. Currently the hypervisor will wait indefinitely for the SYNC
to set the SYNC_COMP_COMPLETE bit. In practice, this case deadlock as
the hypervisor holds the host lock while waiting for the SYNC.

To avoid deadlock, adjust the algorithm to time out after a given number
of reads of the SYNC_COMP register (new constant SYNC_TIMEOUT_BASE).
This can be a small number as most attempts succeed after a single read
of the SFR.

If the wait-loop times out, the hypervisor will try again, multiplying
the maximum number of SFR reads with SYNC_TIMEOUT_MULTIPLIER each time.
This number was selected to grow quickly, in case there is a lot of DMA
traffic that would be slowing down the SYNC request.

Finally, if the hardware does not set the bit even after
SYNC_MAX_RETRIES, the algorithm will give up to avoid deadlock. The
value was selected so that the worst-case time spent in
__wait_for_invalidation_complete() remains tolerable.

Bug: 250727777
Bug: 254213966
Signed-off-by: David Brazdil <dbrazdil@google.com>
Change-Id: I00098753bcc46a894943bbdb3a61acc3a8e5e5d2