includes: move openssl headers to include/u-boot

commit 18b06652cd "tools: include u-boot version of sha256.h"
unconditionally forced the sha256.h from u-boot to be used
for tools instead of the host version. This is fragile though
as it will also include the host version. Therefore move it
to include/u-boot to join u-boot/md5.h etc which were renamed
for the same reason.

cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
diff --git a/common/image.c b/common/image.c
index 828b0af..11b3cf5 100644
--- a/common/image.c
+++ b/common/image.c
@@ -34,7 +34,7 @@
 #endif
 
 #include <u-boot/md5.h>
-#include <sha1.h>
+#include <u-boot/sha1.h>
 #include <asm/errno.h>
 #include <asm/io.h>