KVM: arm64: Tweak parameters of guest cache maintenance functions

Adjust the parameter "kvm_pfn_t pfn" of __clean_dcache_guest_page
and __invalidate_icache_guest_page to "void *va", which paves the
way for converting these two guest CMO functions into callbacks in
structure kvm_pgtable_mm_ops. No functional change.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210617105824.31752-4-wangyanan55@huawei.com