cpu: Add MPC83xx CPU driver

Add a CPU driver for the MPC83xx architecture.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 6fbe8c4..f97ce48 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -1325,7 +1325,9 @@
 /* In misc.c */
 void _nmask_and_or_msr(unsigned long nmask, unsigned long or_val);
 
+#ifndef CONFIG_CPU_MPC83XX
 int prt_83xx_rsr(void);
+#endif
 
 #endif /* ndef ASSEMBLY*/