ARM: OMAP: Add some extra #defines for Amstrad Delta

This patch adds some further #defines regarding GPIOs and latch bits for
the Amstrad Delta; the drivers that use them will be submitted at a
later date but there's no reason not to have the information already
there and available for use.

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