[FEATURE] Feature request - Higher half mapping for MMIO

[bSchnepp]

Issue Checklist

• [x] A related or similar issue is not already marked as open
• [x] Another issue describing a similar feature has not already been marked as wontfix or closed
• [x] This feature is not already present in the software

===================================================== Feature Description The kernel should isolate device MMIO from ordinary memory, and have it virtually mapped in the higher half area. This will (eventually) allow remapping of the whole kernel there, and begin properly using the MMU.

Feature Benefits List the reasons why this feature would be beneficial

• Process isolation
• Performance

Use case examples List examples where this feature could be useful for end users.

• Programs are more strongly separated

Additional information Any additional information should be placed here.

[bSchnepp]

Implemented in 4f2d774d5b1b1018ea809ce8caeb5fd43254b99f, but this needs to be generalized for all MMIO.

[bSchnepp]

Merged as of a91ea51bebd6d65cbc4abfd3a9fd255aa2ed82b0