dt-bindings: mmc: meson-gx: support specifying cd interrupt

Support passing a second interrupt as card detect interrupt.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/1c5996a5-491f-39d6-b120-bbef86473729@gmail.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>