net: ethernet: ti: cpsw: drop CONFIG_TI_CPSW_ALE config option

All TI drivers CPSW/NETCP can't work without ALE, hence simplify
build of those drivers by always linking cpsw_ale and drop
CONFIG_TI_CPSW_ALE config option.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>