iproute2: de-bash its scripts to remove the bash dependency

iproute2: de-bash its scripts to remove the bash dependency

If we build a minimal image with iproute2 installed, the following
error will appear during rootfs.

error: Can't install iproute2-3.10.0-r0.0@i586: no package provides /bin/bash

The problem is that iproute2 has an implicit dependency on 'bash'.
This dependency is from per-file dependency checking.

Patch two scripts, ifcfg and rtpr, from iproute2 to remove the bash
specific syntax.

[YOCTO #5415]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>