usb: dwc3: set SUSPHY bit for all cores

It is recommended to set USB3 and USB2 SUSPHY bits to '1' after the core
initialization is completed above the dwc3 revision 1.94a.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>