Drop providing the virtual package ip by busybox which was added in commit
1cec4d4ef0.
Letting busybox provide the virtual package ip is not optimal for the
following reasons :
- Applications depending on ip expect either the ip-full or
ip-tiny package to be enabled.
- Busybox ip applet cannot be added or removed at runtime
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>