xen/arm: smmuv3: Revert patch related to XArray

xen/arm: smmuv3: Revert patch related to XArray

XArray is not implemented in XEN revert the patch that introduce the
XArray code in SMMUv3 driver.

XArray is added in preparation for sharing some ASIDs with the CPU,

As XEN support only Stage-2 translation, ASID is used for Stage-1
translation there is no consequences of reverting this patch for XEN.

Once XArray is implemented in XEN this patch can be added in XEN if XEN
supports Stage-1 translation.

Reverted the commit 0299a1a81ca056e79c1a7fb751f936ec0d5c7afe

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>