kernel/vm: Make some functions static and remove dead code

[astalke]

Description

• MISRA
• Make _page_map and _page_initSizes static
• Remove dead function _page_showSizes

Fixes: https://github.com/phoenix-rtos/phoenix-rtos-project/issues/1071 Fixes: https://github.com/phoenix-rtos/phoenix-rtos-project/issues/1072 Fixes: https://github.com/phoenix-rtos/phoenix-rtos-project/issues/1073 Fixes: https://github.com/phoenix-rtos/phoenix-rtos-project/issues/1080 Fixes: https://github.com/phoenix-rtos/phoenix-rtos-project/issues/1082

JIRA: RTOS-836

Motivation and Context

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] Chore (refactoring, style fixes, git/CI config, submodule management, no code logic changes)

How Has This Been Tested?

• [ ] Already covered by automatic testing.
• [ ] New test added: (add PR link here).
• [x] Tested by hand on: ia32-generic-qemu

Checklist:

• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing linter checks and tests passed.
• [x] My changes generate no new compilation warnings for any of the targets.

Special treatment

• [ ] This PR needs additional PRs to work (list the PRs, preferably in merge-order).
• [ ] I will merge this PR by myself when appropriate.

[github-actions[bot]]

Unit Test Results

7 460 tests  ±0   6 745 :white_check_mark: ±0   39m 7s :stopwatch: +6s   420 suites ±0     715 :zzz: ±0      1 files   ±0       0 :x: ±0 

Results for commit d82e54df. ± Comparison against base commit a3369fa2.

:recycle: This comment has been updated with latest results.

[niewim19]

@damianloew is this PR`s CI able to be repaired by rerunning campaign? Or do we hold it as error case?

[damianloew]

@damianloew is this PR`s CI able to be repaired by rerunning campaign? Or do we hold it as error case?

Re-run should help, I've already done it :)