ARM: OMAP2+: omap2plus_defconfig: Enable CPSW support

Enable CPSW support in defconfig which is present in AM33xx SoC

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>