Makefile: make GBDIR able to be overloaded on the command line

Only use the default version if there is not an environment variable
version.

Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
gbsim: mention build dependencies in README

gbsim depends on libusbg (and as a result, libconfig) so
document that fact in the README build instructions.

Signed-off-by: Matt Porter <mporter@linaro.org>
Merge pull request #1 from gregkh/makefile_fix

Makefile: make GBDIR able to be overloaded on the command line
LICENSE: fix copyright holder information

Fill in the copyright holder information and drop
the unneeded all rights reserved.

Signed-off-by: Matt Porter <mporter@linaro.org>