drivers: i3c: fix/improve Doxygen

- Use references whenever possible instead of literals (e.g. `@c`)
- Remove incorrect usages of `@see`
- Fix incorrect usage of INTERNAL_HIDDEN blocks
- Detail Kconfig-dependent options with `@kconfig{}`
- Other minor enhancements

Ref. https://www.doxygen.nl/manual/autolink.html



Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>