CRISv10: Don't autonegotiate if autonegotiation is off

If autonegotiation was disabled, we still set the
BMCR_ANENABLE and BMCR_ANRESTART, which resulted in autonegotiation
never being disabled.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reported-by: Julia Lawall <julia@diku.dk>