ARM: dts: at91: drop unneeded status from gpio-keys

Nodes do not need explicit status=okay.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220616005333.18491-40-krzysztof.kozlowski@linaro.org