arm: socfpga: clean up board config files

Remove outdated defines (not used any more, outdated due to DM
conversion) from various socfpga files in include/config.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Acked-by: Marek Vasut <marex@denx.de>
Series-version: 3
Series-changes: 2
- added (this) patch with further cleanups to the socfpga board config
  files