dt-bindings: mfd: dlg,da9063: Update watchdog child node

Update watchdog child node by referring to dlg,da9062-watchdog binding
file and drop its definition from this file.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240131102656.3379-3-biju.das.jz@bp.renesas.com


Signed-off-by: Lee Jones <lee@kernel.org>