omap1: Add omap7xx USB support

This change implements USB client side support into the HTC
Herald board configuration.  It uses a similar, but updated
algorithm to initialize the USB as is used in the linwizard
project.

Signed-off-by: Cory Maccarrone <darkstar6262@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>