Flip the IVL_SVL_SELECT bit correctly based on the VLAN enable status,
the default is to perform Shared VLAN learning instead of Individual
learning.

Fixes: 1da6df85 ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>