uboot-imx

arm64: zynqmp: Setup clock-output-names for si570 chips

If there are more instances of si570 clock-output-names property
should be used for differentiation of clock output.
The patch is adding this optional properties for all zynqmp boards with
si570 chip.

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