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/drivers/spi/mpc8xxx_spi.c b/drivers/spi/mpc8xxx_spi.c
index e48debb..8aedd5e 100644
--- a/drivers/spi/mpc8xxx_spi.c
+++ b/drivers/spi/mpc8xxx_spi.c
@@ -8,6 +8,7 @@
 #include <clk.h>
 #include <dm.h>
 #include <errno.h>
+#include <log.h>
 #include <malloc.h>
 #include <spi.h>
 #include <asm/mpc8xxx_spi.h>