dpll: zl3073x: Refactor DPLL initialization

dpll: zl3073x: Refactor DPLL initialization

Refactor DPLL initialization and move DPLL (de)registration, monitoring
control, fetching device invariant parameters and phase offset
measurement block setup to separate functions.

Use these new functions during device probe and teardown functions and
during changes to the clock_id devlink parameter.

These functions will also be used in the next patch implementing devlink
flash, where this functionality is likewise required.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Link: https://patch.msgid.link/20250909091532.11790-5-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>