KVM: arm64: Drop the requirement for XARRAY_MULTI

Now that we don't use xa_store_range() anymore, drop the added
complexity of XARRAY_MULTI for KVM. It is likely still pulled
in by other bits of the kernel though.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-12-maz@kernel.org


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>