board/b4qds: VID support

board/b4qds: VID support

The fuse status register provides the values from on-chip
voltage ID efuses programmed at the factory.
These values define the voltage requirements for
the chip. u-boot reads FUSESR and translates the values
into the appropriate commands to set the voltage output
value of an external voltage regulator.

B4860QDS has a PowerOne ZM7300 programmable digital Power
Manager which is programmed as per the value read from
the fuses.

Reference for this code is taken from t4qds VID implementation.

Signed-off-by: Shaveta Leekha <shaveta@freescale.com>
Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>