Add support for non-contiguous physical page mapping

[sangho2]

This PR introduces a vmap subsystem to the LVBS platform to map non-contiguous physical page frames into virtually contiguous addresses.

Changes

• Add map_non_contiguous_phys_frames which is similar to existing map_phys_frame_range except that this new function is for non-contiguous physical page frames.
• Reserve a 1 TB VA window for vmap and vunmap
• Maintain separate hash tables for tracking PA<->VA for VMAPs (mm/vmap.rs)

[github-actions]

🤖 SemverChecks 🤖 ⚠️ Potential breaking API changes detected ⚠️

Click for details

--- failure enum_variant_missing: pub enum variant removed or renamed ---

Description:
A publicly-visible enum has at least one variant that is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/enum_variant_missing.ron

Failed in:
  variant PhysPointerError::NonContiguousPages, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/3cfa0fa5600bfc4545b7b6fa086c315678c66151/litebox_common_linux/src/vmap.rs:170