env: Implement support for AES encryption into fw_* tools

Implement support for encrypting/decrypting the environment block
into the tools/env/fw_* tools. The cipher used is AES 128 CBC and
the implementation depends solely on components internal to U-Boot.

To allow building against the internal AES library, the library did
need minor adjustments to not include U-Boot's headers which are not
wanted to be included and define missing types.

Signed-off-by: Marek Vasut <marex@denx.de>

lib/aes.c

@@ -22,7 +22,11 @@
  * REDISTRIBUTION OF THIS SOFTWARE.
 */
 
+#ifndef USE_HOSTCC
 #include <common.h>
+#else
+#include <string.h>
+#endif
 #include "aes.h"
 
 /* forward s-box */