common: Drop log.h from common header

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/cpu/mpc86xx/cpu.c b/arch/powerpc/cpu/mpc86xx/cpu.c
index fe35744..9f5bce3 100644
--- a/arch/powerpc/cpu/mpc86xx/cpu.c
+++ b/arch/powerpc/cpu/mpc86xx/cpu.c
@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <cpu_func.h>
+#include <log.h>
 #include <time.h>
 #include <vsprintf.h>
 #include <watchdog.h>