cros_ec: Adjust to use v1 vboot context only

At present there are no users of the 64-byte v2 context. The v1 context is
only 16 bytes long and currently an error is raised if too much data is
returned from the EC.

Update the code to limit the size to 16 bytes.

Signed-off-by: Simon Glass <sjg@chromium.org>
1 file changed