CI does not catch `enum`s with non-capitalized letters

[Thalley]

Summary

https://docs.zephyrproject.org/latest/contribute/style/code.html refers to the Linux coding style which has https://www.kernel.org/doc/html/v4.10/process/coding-style.html#macros-enums-and-rtl:

12) Macros, Enums and RTL

Names of macros defining constants and labels in enums are capitalized.

#95678 demonstrates that this isn't ensured in CI

Describe the solution you'd like

Not sure if it should checkpatch.pl or something else that needs to verify this, but our compliance check should check for and disallow enums without capitalized letters

Alternatives

No response

Additional Context

No response