dpll: zl3073x: Add support to get/set priority on input pins

dpll: zl3073x: Add support to get/set priority on input pins

Add support for getting and setting input pin priority. Implement
required callbacks and set appropriate capability for input pins.
Although the pin priority make sense only if the DPLL is running in
automatic mode we have to expose this capability unconditionally because
input pins (references) are shared between all DPLLs where one of them
can run in automatic mode while the other one not.

Co-developed-by: Prathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: Prathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20250704182202.1641943-11-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>