linux-phytec-ti

dt-bindings: Create Documentation for NSP DT bindings

Add the documentation for the Broadcom Northstar Plus device tree
bindings.

Signed-off-by: Jon Mason <jonmason@broadcom.com>
Acked-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>