1 MMC/SD/SDIO slot directly connected to a SPI bus
4 - compatible : should be "mmc-spi-slot".
5 - reg : should specify SPI address (chip-select number).
6 - spi-max-frequency : maximum frequency for this device (Hz).
7 - voltage-ranges : two cells are required, first cell specifies minimum
8 slot voltage (mV), second cell specifies maximum slot voltage (mV).
9 Several ranges could be specified.
10 - gpios : (optional) may specify GPIOs in this order: Card-Detect GPIO,
16 compatible = "fsl,mpc8323rdb-mmc-slot",
19 gpios = <&qe_pio_d 14 1
21 voltage-ranges = <3300 3300>;
22 spi-max-frequency = <50000000>;