Merge branch kvm-arm64/smccc-filter-cleanups into kvmarm/next

Merge branch kvm-arm64/smccc-filter-cleanups into kvmarm/next

* kvm-arm64/smccc-filter-cleanups:
  : Cleanup the management of KVM's SMCCC maple tree
  :
  : Avoid the cost of maintaining the SMCCC filter maple tree if userspace
  : hasn't writen a rule to the filter. While at it, rip out the now
  : unnecessary VM flag to indicate whether or not the SMCCC filter was
  : configured.
  KVM: arm64: Use mtree_empty() to determine if SMCCC filter configured
  KVM: arm64: Only insert reserved ranges when SMCCC filter is used
  KVM: arm64: Add a predicate for testing if SMCCC filter is configured

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