ARM: OMAP1: ams-delta: make board header file local to mach-omap1

Now as the board header file is no longer included by drivers, move it
to the root directory of mach-omap1.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>