dpll: zl3073x: add zl3073x_ref_state_update helper

dpll: zl3073x: add zl3073x_ref_state_update helper

Extract the per-reference monitor status HW read into a dedicated
zl3073x_ref_state_update() helper in the ref module. Rename
zl3073x_dev_ref_status_update() to zl3073x_dev_ref_states_update()
and use the new helper in it. Call it from zl3073x_ref_state_fetch()
as well so that mon_status is initialized at device startup. This
keeps direct register access and struct field writes behind the ref
module's interface, consistent with the state management pattern
used for other ref operations.

Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Link: https://patch.msgid.link/20260315174224.399074-3-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>