KVM: arm64: Handle huge mappings for np-guest CMOs

KVM: arm64: Handle huge mappings for np-guest CMOs

clean_dcache_guest_page() and invalidate_icache_guest_page() accept a
size as an argument. But they also rely on fixmap, which can only map a
single PAGE_SIZE page.

With the upcoming stage-2 huge mappings for pKVM np-guests, those
callbacks will get size > PAGE_SIZE. Loop the CMOs on a PAGE_SIZE basis
until the whole range is done.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/r/20250521124834.1070650-2-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>