u-boot: fit: add support to decrypt fit with aes

This commit add to u-boot the support to decrypt
fit image encrypted with aes. The FIT image contains
the key name and the IV name. Then u-boot look for
the key and IV in his device tree and decrypt images
before moving to the next stage.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/tools/Makefile b/tools/Makefile
index 051127a..99be724 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -77,7 +77,7 @@
 					rsa-mod-exp.o)
 
 AES_OBJS-$(CONFIG_FIT_CIPHER) := $(addprefix lib/aes/, \
-					aes-encrypt.o)
+					aes-encrypt.o aes-decrypt.o)
 
 ROCKCHIP_OBS = lib/rc4.o rkcommon.o rkimage.o rksd.o rkspi.o