Add libtool to dependency list in README
Add libtool to dependency list in README

libtools is required by some of the tools that tegra-uboot-flasher can
build. Add it to the list of dependencies.

Signed-off-by: Stephen Warren <5ef2a23ba3aff51d1cfc8c113c1ec34b608b3b13@nvidia.com>

NVIDIA/tegra-uboot-flasher-scripts