uboot-imx

ARM64: zynqmp: Select SYS_CONFIG_NAME via Kconfig

This option enable adding new platform suport just by adding defconfig
and DTS file which will target generic configuration for SoC.
Make no sense to extend Kconfig just create a pointer between DTS and
configuration file.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>