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/soft_spi.c b/drivers/spi/soft_spi.c
index b80f810..af0dd71 100644
--- a/drivers/spi/soft_spi.c
+++ b/drivers/spi/soft_spi.c
@@ -13,6 +13,7 @@
 #include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>
+#include <log.h>
 #include <malloc.h>
 #include <spi.h>
 #include <asm/gpio.h>