[U-Boot] [RESEND PATCH 1/2] TI: DaVinci DA850 EVM: add information regarding DA850 in README.davinci

[Paulraj, Sandeep]

> 
> The README.davinci in documentation folder is missing information
> regarding DA850 which is a supported DaVinci device.
> 
> Add this information.
> 
> Signed-off-by: Sekhar Nori <nsekhar at ti.com>
> ---

Pushed to u-boot-ti


--Sandeep