ANDROID: KVM: arm64: Fix kvm_pgtable_stage2_relax_perms

Permission relaxation checks for prot consistency where alid inputs are
a subset of RWX. Sadly, a typo made that verification a passthrough.

Bug: 278749606
Fixes: e4dd74e2 ("ANDROID: KVM: arm64: Allow setting {P,U}XN in stage-2 PTEs")
Change-Id: I161646f08219ad3a04eba478162cc87aa32cffb4
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>