meta-agl-uhmi-demo: Removed fixed configuration

meta-agl-uhmi-demo: Removed fixed configuration

Rather than having a static IPs assigned let us use DHCP by default.
This is more in common with the other images we have available. Also
qemu can provide DHCP server so we wouldn't really need this.

A fixed IP configuration can't really work out, when we have other
network class in the system, meaning that this won't really work unless
you have the same class in your network already we that's not case.

Change-Id: I19aeecdac2f8e5bcade1ee9e4c130880e710b85b
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>