arm64: mm: Represent physical memory with phys_addr_t and resource_size_t

This is a type-correctness cleanup to MMU/boot code that replaces
several instances of void * and u64 with phys_addr_t (to represent
addresses) and resource_size_t (to represent sizes) to emphasize that
the code in question concerns physical memory specifically.

The rationale for this change is to improve clarity and readability in
a few modules that handle both types (physical and virtual) of address
and differentiation is essential.

I have left u64 in cases where the address may be either physical or
virtual, where the address is exclusively virtual but used in heavy
pointer arithmetic, and in cases I may have overlooked. I do not
necessarily consider u64 the ideal type in those situations, but it
avoids breaking existing semantics in this cleanup.

This patch provably has no effect at runtime: I have verified that
.text of vmlinux is identical after this change.

Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>