[qca-nss-clients] Changes in GRE to enable eogre Configuration.

Added fields in cfg struct to enable custom next dev in both direction.
Added code to configure custom next dev in outer direction.

Change-Id: I70748c232e6ae1a87f98382f32caa91fc5703155
Signed-off-by: Suruchi Suman <surusuma@codeaurora.org>
4 files changed