apalis/colibri_t30: fix MMC/SD card detect GPIOs

This fixes the MMC/SD card detect GPIOs for Apalis T30 which got broken
by the following commit:

2b2b50bc "dm: tegra: dts: Use TEGRA_GPIO() macro for all GPIOs"

While at it also re-add the comments describing which particular
Apalis/Colibri pins those GPIOs are on.

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>