u-boot-spl-zynq-init.inc: Add variable to trigger platform overwriting
u-boot-spl-zynq-init.inc: Add variable to trigger platform overwriting

Add the "FORCE_PS7INIT" variable to overwrite the targeted platform with
the machines preferred platform-init provider. This allows for reference
designs to override the platform-init for boards with existing support
in U-Boot without having to modify U-Boot configuration.

Signed-off-by: Nathan Rossi <2e8aa918660411855c6d44d5bb2da677aa033255@nathanrossi.com>

Xilinx/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx,nathanrossi/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx,Xilinx/meta-xilinx,Xilinx/meta-xilinx,Xilinx/meta-xilinx,nathanrossi/meta-xilinx