cmd: broadcom: add command for chimp handshake

Add command for chimp handshake.
Handshake is used to know chimp is loaded and booted successfully.

Signed-off-by: Bharat Kumar Reddy Gooty <bharat.gooty@broadcom.com>
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
3 files changed