Consistent notation for VAddr/PAddr

[hawkw]

Currently, we tend to format both virtual (VAddr) and physical (PAddr) addresses using the "{:#p}" format specifier for pointers. This works fine, but makes telling whether an address is physical or virtual difficult when reading through logs, et cetera.

It'd be nice if we could have a consistent notation for these. I suggest possibly replacing "0xff00" with "Pxff00 for physical addresses and Vxff00 for virtual addresses, or appending a P/V to the end of the hex address, like 0xff00_p.

[hawkw]

Someone who knows how string formatting works in Rust could probably implement this fairly easily without any OS dev knowledge.

Therefore, I'm tagging it as "easy" and "help wanted", in case anybody's looking for a good issue for a first-time contributor...