[PATCH] Prepare paddr_to_vaddr() for arch-specific p2v conversion

Currently, conversion from physical address to virtual address in
--mem-usage option is "paddr + PAGE_OFFSET", which was written for
x86_64, but it's not suitable especially for arm64.

This patch introduces paddr_to_vaddr() macro to get prepared for
arch-specific physical to virtual conversion.

Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Kazuhito Hagio <k-hagio@ab.jp.nec.com>