ARM: OMAP: Readd Amstrad Delta USB support

One of the recent merges from mainline removed the Amstrad Delta USB
support. This patch adds it back in; it's the same as was in
2.6.16-omap2.

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Tony Lindgren <tony@atomide.com>