dt-bindings: mfd: da9062: Update watchdog description

Update watchdog description by referring to dlg,da9062-watchdog binding
file.

Update MAINTAINERS entries.

Fixes: bd888a43

 ("dt-bindings: watchdog: da9062-wdt: convert txt to yaml")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240131102656.3379-2-biju.das.jz@bp.renesas.com


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