ARM: zynq: use "select" instead of default value in defconfig

All the Zynq boards have switch to Driver Model.
"select DM" is better than default value in each defconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
8 files changed