mvebu: fix usb port leds

mvebu: fix usb port leds

All mvebu boards have three USB LEDs. The first one is used for the
USB1 port.

There are two LEDs related to the second USB port. The top (bar) LED
gets bright in case any USB device is connected to the second USB port.

If the connected device is an USB 3 (SuperSpeed) device, the small dot
LED bellow the "bar" LED gets also bright.

While at it, use a name for the USB LEDs that matches the names printed
on the case.

Fixes: FS#423, FS#425
Signed-off-by: Kabuli Chana <newtownbuild@gmail.com>
Signed-off-by: Mathias Kresin <dev@kresin.me>