common: Drop linux/printk.h from common header

This old patch was marked as deferred. Bring it back to life, to continue
towards the removal of common.h

Move this out of the common header and include it only where needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/st/common/stm32mp_dfu.c b/board/st/common/stm32mp_dfu.c
index 1cf4a3d..faee953 100644
--- a/board/st/common/stm32mp_dfu.c
+++ b/board/st/common/stm32mp_dfu.c
@@ -14,6 +14,7 @@
 #include <mtd.h>
 #include <mtd_node.h>
 #include <asm/arch/stm32prog.h>
+#include <linux/printk.h>
 
 #define DFU_ALT_BUF_LEN SZ_1K