Add option to enable/disable navring (1/2)

This will add an option to toggle navigation ring.

If the navigation bar is disabled then a standalone
navigation ring is added.

Change-Id: I527c25b11bcb2c5f4b70799055f97bab65ed2cec
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>