arm: atmel: remove the config.mk file

remove the config.mk file
move text base define to board config file for following boards
  - at91sam9m10g45ek
  - at91sam9x5ek

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
4 files changed