submodules: update meta-nilrt hash to pull fixup

Signed-off-by: Alex Stewart <alex.stewart@ni.com>

nilrt: Update layers for 2016 release

Signed-off-by: Brad Mouring <brad.mouring@ni.com>

README.txt: add post-install instructions

NI's software installs include a postinst script that fixes up the
serial console on Zynq, and other software like NI Auth that enables
login to accounts like admin on all targets. People using nilrt without
NI software need equivalent steps to be able to log into their targets.

nilrt: add COPYING.MIT file

nilrt is provided under the MIT license.

nibb.sh: Add facilities to compare build information

In order to get a good idea that the image that is created
internally at NI matches what is built through nilrt, provide
some facilities to output useful image information for comparison.

Signed-off-by: Brad Mouring <brad.mouring@ni.com>