Functions added to support board callbacks for USB init. This
isolates USB manipulations such that it is only touched if USB is
used by U-Boot.
Signed-off-by: Dave Mitchell <dmitchell@appliedmicro.com>
Signed-off-by: Rupjyoti Sarmah <rsarmah@appliedmicro.com>
Signed-off-by: Stefan Roese <sr@denx.de>