arm: omap3: Add HEAD acoustics (HA) board variant omap3_ha to tao3530

The Head acoustics (HA) baseboard used the Technexion TAO3530 SOM
and has only some minor differences to the Technexion Thunder baseboard.
This patch adds support for this HA baseboard / TAO3530 as the "omap3_ha"
build target.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Tapani Utriainen <tapani@technexion.com>
Cc: Thorsten Eisbein <thorsten.eisbein@head-acoustics.de>
Cc: Tom Rini <trini@ti.com>