drm/radeon/kms/evergreen: work around bad data in some i2c tables

The 7th entry in a lot of evergreen i2c gpio tables is partially
zeroed.  Fix the entry.

Should fix the missing ddc entry in:
https://bugs.freedesktop.org/show_bug.cgi?id=29255



Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>