DaVinci DM6467: Enhance board Support

Support for DM6467 was incomplete and the build failed
as well. Patches were sent to the list but have not been
added. This enhances the DM6467 support.
Some more patches will need to be sent to bring
it in line with what is available in internal TI
trees


Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>