ANDROID: KVM: arm64: Don't recycle non-default PTEs

When recycling host stage-2 page-table pages, we currenly blindly
unmap all 'non-moveable' regions. To prepare the ground for allowing the
mapping of those regions with non-default attributes, let's switch to
using the recently introduced kvm_pgtable_stage2_reclaim_leaf() helper
which will only reclaim pages containing PTEs with default attributes.

Bug: 264070847
Change-Id: I4a441a20abe84d2405efcfa403908078c10be841
Signed-off-by: Quentin Perret <qperret@google.com>