Merge branch 'dpll-zl3073x-add-ref-sync-pair-support'

Merge branch 'dpll-zl3073x-add-ref-sync-pair-support'

Ivan Vecera says:

====================
dpll: zl3073x: add ref-sync pair support

This series adds Reference-Sync pair support to the ZL3073x DPLL driver.
A Ref-Sync pair consists of a clock reference and a low-frequency sync
signal (e.g. 1 PPS) where the DPLL locks to the clock reference but
phase-aligns to the sync reference.

Patches 1-3 are preparatory cleanups and helper additions:
- Clean up esync get/set callbacks with early returns and use the
  zl3073x_out_is_ndiv() helper
- Convert open-coded clear-and-set bitfield patterns to FIELD_MODIFY()
- Add ref sync control and output clock type accessor helpers

Patch 4 adds the 'ref-sync-sources' phandle-array property to the
dpll-pin device tree binding schema and updates the ZL3073x binding
examples.

Patch 5 implements the driver support:
- ref_sync_get/set callbacks with frequency validation
- Automatic sync source exclusion from reference selection
- Device tree based ref-sync pair registration

Tested and verified on Microchip EDS2 (pcb8385) development board.
====================

Link: https://patch.msgid.link/20260408102716.443099-1-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>