gdsys: drivers: Add gdsys_rxaui_ctrl driver

Add a driver for RXAUI control on IHS FPGAs.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index d774569..be900cf 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -263,5 +263,9 @@
 
 endif
 
-
+config GDSYS_RXAUI_CTRL
+	bool "Enable gdsys RXAUI control driver"
+	depends on MISC
+	help
+	  Support gdsys FPGA's RXAUI control.
 endmenu