doc: man-page for optee commands

Provide a man-page for the optee command.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
2 files changed