uboot-imx

ARM: tegra: use new generic $bootcmd

Replace the custom $bootcmd with that from <config_distro_bootcmd.h>.
There should be no functional change, since the new generic $bootcmd was
derived strongly from tegra-common-post.h.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>