fpga: zynqmp: add str2flags call

Add a call to convert FPGA "compatible" string to a binary flag.

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Tested-by: Ricardo Salveti <ricardo@foundries.io>
Tested-by: Adrian Fiergolski <adrian.fiergolski@fastree3d.com>
Link: https://lore.kernel.org/r/20220722141614.297383-5-oleksandr.suvorov@foundries.io


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