rockchip: rk33xx: Drop ROCKCHIP_USB2_PHY on boards without it

The 64 bit rk33xx chips don't have the ROCKCHIP_USB2_PHY IP so
drop the configs as they were likely copied over from other
boards during enablement.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>