firmware: xilinx: export the feature check of zynqmp firmware

Export the zynqmp_pm_feature(), so it can be use by other as to get API
version available in firmware.

Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Abhyuday Godhasara <abhyuday.godhasara@xilinx.com>
Link: https://lore.kernel.org/r/20211026042525.26612-4-abhyuday.godhasara@xilinx.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>