net: rpl: Add RPL header revert utility

When a nodes receive a packet with RPL option in IPv6 HBH, it's need
to be reverted with node flags, instance id and sender rank.

Change-Id: Ic49c8e84c7846dc02728c120078506f6d7411e52
Signed-off-by: Ravi kumar Veeramally <ravikumar.veeramally@linux.intel.com>