Notice that the condition to use ia64 if 64bit is not needed
because it already exists in parse_system_map

use the correct size, symbol, shofts for arm64.
Don't assume first dt entry cannot be zero.

The main pagetable volatility finds is used for TTBR1, it is used to
translate all kernel-space addesses.
Userspace addresses should be translated with the per-process dtb, which
is used for TTBR0.

An address is known to be kernel or userspace by looking at it's high
bit.

This implementation parses only the user-pagetable, to avoid returning
the entire kernel mapping for each user process.