commit afceb931 upstream.

Some r4xx chips have the wrong frev in the
DVOEncoderControl table.  It should always be 1
on r4xx.  Fixes modesetting on DVO on r4xx chips
with the bad frev.

Reported by twied on #radeon.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>