arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers

arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers

Despite KVM now being able to deal with XS-tagged TLBIs, we still don't
expose these feature bits to KVM.

Plumb in the feature in ID_AA64ISAR1_EL1.

Fixes: 0feec7769a63 ("KVM: arm64: nv: Add handling of NXS-flavoured TLBI operations")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241031083519.364313-1-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>