ANDROID: KVM: arm64: Fix pKVM psci_mem_protect account

When bringing pkvm_checked_mem_transition, the number of pages were
foolishly multiplied by the PAGE_SIZE. This lead to an incorrect number
of pages and by extension leaving the PSCI memory protection against
warm reset on.

Bug: 278749606
Bug: 243642516
Fixes: 20211228 ("ANDROID: KVM: arm64: pkvm_checked_mem_transition for mem_protect share transitions")
Reported-by: Will Deacon <willdeacon@google.com>
Change-Id: Id351d0e9d7818b2c6431e5e1b4464f6dc201cc7f
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>