ux500: remove build-time changing macros

To allow the possiblity of building U8500 and U5500 support in the same
image.

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
[Rebased to latest changes in Russells tree]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>