dpll: spec: Add Netlink spec in YAML

Add a protocol spec for DPLL.
Add code generated from the spec.

v9->v10:
- add DPLL_MODE_FREERUN
- add pin-phase-shift, pin-phase-adjust

v8->v9:
- regenerate policy max values
- add missing enum descriptions
- split pin-parent nest:
  - pin-parent-device - for configuration of pin-device tuple
  - pin-parent-pin - for configuration od pin-pin tuple
- fix typos:
  - s/working-modes/working modes/
  - s/differentiate/differentiates/
  - s/valid input, auto selected by dpll/input pin auto selected by dpll/
- remove FREERUN and HOLDOVER modes

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Michal Michalik <michal.michalik@intel.com>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>

Author: Vadim Fedorenko