mel: set ADE_VERSION with fixed timestamp

This ensures that the ADE_VERSION used in create-ade aligns with the
ADE_VERSION used in ade-support.

JIRA: SB-3335

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Merge pull request #301 from kergoth/sb-3335

mel: set ADE_VERSION with fixed timestamp