add sysfs document for fpga bridge class

Add documentation for new FPGA bridge class's sysfs interface.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/Documentation/ABI/testing/sysfs-class-fpga-bridge b/Documentation/ABI/testing/sysfs-class-fpga-bridge
new file mode 100644
index 0000000..312ae2c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-fpga-bridge
@@ -0,0 +1,11 @@
+What:		/sys/class/fpga_bridge/<bridge>/name
+Date:		January 2016
+KernelVersion:	4.5
+Contact:	Alan Tull <atull@opensource.altera.com>
+Description:	Name of low level FPGA bridge driver.
+
+What:		/sys/class/fpga_bridge/<bridge>/state
+Date:		January 2016
+KernelVersion:	4.5
+Contact:	Alan Tull <atull@opensource.altera.com>
+Description:	Show bridge state as "enabled" or "disabled"