OMAP4: Networking: Defconfig Support

Enable KS8851 SPI support +

 Networking Support
  - Packet Socket
  - TCP/IP

 Network Filesystems
  - NFS Client
  - Root Filesystem on NFS

Signed-off-by: Abraham Arce <x0066660@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>