powerpc/mpc5121: Update device tree for MPC5121ADS evaluation board

Current device tree is only bare bones.  This patch adds nodes to make
it a complete tree for the MPC5121ads.

Added nodes include:
    mbx      - opengl coprocessor
    nfc      - nand flash controller
    cpld-pic - on board cpld
    rtc
    clock    - clock control
    pmc      - power management control
    gpio
    mscan    - can module
    i2c
    axe      - audio coprocessor
    display  - display interface unit
    mdio
    ethernet
    usb
    ioctl    - pin config
    pata
    ac97     - PSC configured as AC97
    pscfifo  - psc fifo configuration
    dma
    pci

Fix typo in header changing MDS to ADS.

Add a compatible property of the form "fsl,mpc5121-..."
to nodes missing one.

Changed localbus compatible to fsl,mpc5121-localbus, this does
not break anything because the only code that uses it finds it
via the node name, not compatible.

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>