Enabled default dts files on respective pre-board config
files this is way MAKEALL will works. and it's upto user
to build specific dts by specifying at build time.
$ make zynq_zc70x_config
$ make --> with default dts zynq-zc702.dts
or
$ make DEVICE_TREE=zynq-zc702 --> Same configuration with zynq-zc706.dts
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
CONFIG_SYS_SDRAM_SIZE is specific to a board hence moved
to specific pre-config board files.
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>