clk: Add MPC83xx clock driver

Add a clock driver for the MPC83xx architecture.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/arch/powerpc/cpu/mpc83xx/speed.c b/arch/powerpc/cpu/mpc83xx/speed.c
index f094528..39bc1c5 100644
--- a/arch/powerpc/cpu/mpc83xx/speed.c
+++ b/arch/powerpc/cpu/mpc83xx/speed.c
@@ -6,6 +6,8 @@
  * Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
  */
 
+#ifndef CONFIG_CLK_MPC83XX
+
 #include <common.h>
 #include <mpc83xx.h>
 #include <command.h>
@@ -590,3 +592,5 @@
 	"print clock configuration",
 	"    clocks"
 );
+
+#endif