sfxge(4): fix V1 licensing MCDI operations

Implementation of the MCDI commands for Siena boards was requesting
the wrong operation.

Submitted by: Richard Houldsworth <rhouldsworth at solarflare.com>
Sponsored by: Solarflare Communications, Inc.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D6370