[U-Boot] OMAP3 Remove unneeded decls

[Tom Rix]

The repo is u-boot-ti and the branch is 'next'.

In the vein of my last patch..

This is cleanup of omap3 board config files.
This is the link to the thread on the list
http://lists.denx.de/pipermail/u-boot/2009-November/064351.html

Not all of the boot_flash_* declarations  are needed by all of
the boards.  The set for each board was minimized by keeping
the declaration of variable used is part of a #define in
the config file. 

This was regression tested with MAKEALL arm and runtested on Zoom2

Tom