mach-snapdragon: move default environment to a file

Make use of CONFIG_DEFAULT_ENV_FILE and move the default qcom
environment to a file under board/qualcomm.

This is much cleaner and means we don't need to recompile on changing
the environment.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
3 files changed