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/common/splash_source.c b/common/splash_source.c
index 2ff1520..f51ca5d 100644
--- a/common/splash_source.c
+++ b/common/splash_source.c
@@ -13,6 +13,7 @@
 #include <fs.h>
 #include <fdt_support.h>
 #include <image.h>
+#include <log.h>
 #include <nand.h>
 #include <sata.h>
 #include <spi.h>