TI: DaVinci: Prepare for da850 support

DA850/OMAP-L138 is a new SoC from Texas Instruments
(http://focus.ti.com/docs/prod/folders/print/omap-l138.html

).
This SoC is similar to DA830/OMAP-L137 in many aspects. Hence
rename the da830 specific files and folders to da8xx to
accommodate DA850/OMAP-L138.

Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Acked-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>