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/MAINTAINERS b/MAINTAINERS
index 9ff3bbe..237a022 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -529,6 +529,7 @@
 F:	drivers/timer/mpc83xx_timer.c
 F:	drivers/cpu/mpc83xx_cpu.c
 F:	drivers/cpu/mpc83xx_cpu.h
+F:	drivers/misc/mpc83xx_serdes.c
 F:	arch/powerpc/cpu/mpc83xx/
 F:	arch/powerpc/include/asm/arch-mpc83xx/