fix: plat/marvell: a3700: Remove encryption password

According to "openssl" manual:
-K key
The actual key to use: this must be represented as a string
comprised only of hex digits. If only the key is specified,
the IV must additionally specified using the -iv option.
When both a key and a password are specified, the key given
with the -K option will be used and the IV generated from the
password will be taken.
It does not make much sense to specify both key and password.

This patch removes "-k 0" parameter from the encryption command
since we are already using "-K" and "-iv" for the key and IV.

Change-Id: Ia333cedaa3207e643c95d2ec7c229f50eeab96db
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Reviewed-on: http://vgitil04.il.marvell.com:8080/60745

Reviewed-by: Igal Liberman <igall@marvell.com>
Tested-by: iSoC Platform CI <ykjenk@marvell.com>
Reviewed-by: Sharon Habet <sharonh@marvell.com>

plat/marvell/a3700/common/a3700_common.mk

@@ -159,12 +159,12 @@ ifeq ($(MARVELL_SECURE_BOOT),1)
 	@truncate -s %16 $(WTMI_MULTI_IMG)
 	@openssl enc -aes-256-cbc -e -in $(WTMI_MULTI_IMG) \
 	-out $(WTMI_ENC_IMG) \
-	-K `cat $(IMAGESPATH)/aes-256.txt` -k 0 -nosalt \
+	-K `cat $(IMAGESPATH)/aes-256.txt` -nosalt \
 	-iv `cat $(IMAGESPATH)/iv.txt` -p
 	@truncate -s %16 $(BUILD_PLAT)/$(BOOT_IMAGE);
 	@openssl enc -aes-256-cbc -e -in $(BUILD_PLAT)/$(BOOT_IMAGE) \
 	-out $(BUILD_PLAT)/$(BOOT_ENC_IMAGE) \
-	-K `cat $(IMAGESPATH)/aes-256.txt` -k 0 -nosalt \
+	-K `cat $(IMAGESPATH)/aes-256.txt` -nosalt \
 	-iv `cat $(IMAGESPATH)/iv.txt` -p
 endif
 	$(DOIMAGETOOL) $(DOIMAGE_FLAGS)