Add an assert to each TC PHY hook that their required power domain is
enabled.

While at it add a comment describing the domains used on each platform
and TC mode.

v2: Fix non kernel-doc multiline comments. (Jani)

Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230323142035.1432621-21-imre.deak@intel.com