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/include/image.h b/include/image.h
index ab93eb6..0a072f5 100644
--- a/include/image.h
+++ b/include/image.h
@@ -886,7 +886,7 @@
 };
 
 #if IMAGE_ENABLE_VERIFY
-# include <rsa-checksum.h>
+# include <u-boot/rsa-checksum.h>
 #endif
 struct checksum_algo {
 	const char *name;