[U-Boot] powerpc/85xx: usb: Limit controllers initialized by usb_init()

[Matthew Bright]

Hi,

I am looking for a way to limit which usb host interfaces are initiali-
zed by usb_init() in order to skip unused interfaces. This is currently
governed CONFIG_USB_MAX_CONTROLLER_COUNT, which is possible to redefine
at the board level. However this doesn't cover more complex cases where
a SoC has multiple host interfaces but a board using that SoC only uses
a subset that is not necessarily contiguous.

Does there currently exist a way to define such behavior, or should the
functionality be added to usb_init() to support this?

Thanks.
Matthew Bright