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/designware_spi.c b/drivers/spi/designware_spi.c
index 2dc1673..09044bd 100644
--- a/drivers/spi/designware_spi.c
+++ b/drivers/spi/designware_spi.c
@@ -10,6 +10,7 @@
  */
 
 #include <common.h>
+#include <log.h>
 #include <asm-generic/gpio.h>
 #include <clk.h>
 #include <dm.h>