Add a new "env" subcommand to the ut command.

This will run unit tests on the env code. This should be targetable to
any device that supports the env features needed for the tests.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Unify the command for running unit tests further by moving the "ut_time"
command over to "ut time".

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>

Unify the command for running unit tests further by moving the "dm test"
command over to "ut dm".

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>

Add a command that all other unit tests should be a sub-command of.
Also include a command that will run all tests.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>