misc: Add MPC83xx serdes driver

Add a driver to configure the SerDes (Serializer/Deserializer) lanes on
the MPC83xx architecture.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index c2b7cc1..bfa5c91 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -288,4 +288,11 @@
 	depends on MISC
 	help
 	  Support gdsys FPGA's IO endpoint driver.
+
+config MPC83XX_SERDES
+	bool "Enable MPC83xx serdes driver"
+	depends on MISC
+	help
+	  Support for serdes found on MPC83xx SoCs.
+
 endmenu