Merge branch 'dpll-add-pin-operational-state'

Ivan Vecera says:

====================
dpll: add pin operational state

Add pin operational state (operstate) to the DPLL subsystem to
separate administrative intent from actual hardware status.

Currently pin-state mixes what the user requested (connected,
selectable, disconnected) with what the hardware is actually doing.
This makes it difficult to diagnose situations where a user sets
a pin as selectable or connected but the hardware cannot use it
due to signal issues.

The new operstate attribute is reported inside the pin-parent-device
nest alongside the existing state and is read-only. Defined values:

  - active: pin is qualified and actively used by the DPLL
  - standby: pin is qualified but not actively used by the DPLL
  - no-signal: pin does not have a valid signal
  - qual-failed: pin signal failed qualification checks

Patch 1 adds the operstate enum, netlink attribute and the
operstate_on_dpll_get callback to the DPLL subsystem. It also
updates Documentation/driver-api/dpll.rst to describe the
separation between admin state and operational state.

Patch 2 implements the callback for ZL3073x input pins using the
reference monitor status register. It also refactors the existing
state_on_dpll_get to return purely administrative state and switches
periodic monitoring to track operstate changes.
====================

Link: https://patch.msgid.link/20260428154907.2820654-1-ivecera@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>