ARM: dts: am57xx-cl-som-am57x: switch to new cpsw switch drv

Switch CompuLab CL-SOM-AM57x board to use new cpsw switch driver. Those
board configured in dual_mac mode by default. Hence, dual_mac mode has been
preserved the same way between legacy and new driver it's safe to switch
drivers.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>