kernel-fitimage: introduce FIT_HASH_ALG

sanitize fitImage hash algorithm selection with FIT_HASH_ALG
switch default hash algorithm from sha1 to sha256

(From OE-Core rev: 8c9d5d59cb1575fac17c461090937df4cbb3d3b5)

Signed-off-by: Ayoub Zaki <ayoub.zaki@embexus.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/kernel-fitimage.bbclass

@@ -50,6 +50,9 @@ python __anonymous () {
 # Options for the device tree compiler passed to mkimage '-D' feature:
 UBOOT_MKIMAGE_DTCOPTS ??= ""
 
+# fitImage Hash Algo
+FIT_HASH_ALG ?= "sha256"
+
 #
 # Emit the fitImage ITS header
 #
@@ -109,7 +112,7 @@ EOF
 # $4 ... Compression type
 fitimage_emit_section_kernel() {
 
-	kernel_csum="sha1"
+	kernel_csum="${FIT_HASH_ALG}"
 
 	ENTRYPOINT="${UBOOT_ENTRYPOINT}"
 	if [ -n "${UBOOT_ENTRYSYMBOL}" ]; then
@@ -142,7 +145,7 @@ EOF
 # $3 ... Path to DTB image
 fitimage_emit_section_dtb() {
 
-	dtb_csum="sha1"
+	dtb_csum="${FIT_HASH_ALG}"
 
 	dtb_loadline=""
 	dtb_ext=${DTB##*.}
@@ -176,7 +179,7 @@ EOF
 # $3 ... Path to setup image
 fitimage_emit_section_setup() {
 
-	setup_csum="sha1"
+	setup_csum="${FIT_HASH_ALG}"
 
 	cat << EOF >> ${1}
                 setup@${2} {
@@ -203,7 +206,7 @@ EOF
 # $3 ... Path to ramdisk image
 fitimage_emit_section_ramdisk() {
 
-	ramdisk_csum="sha1"
+	ramdisk_csum="${FIT_HASH_ALG}"
 	ramdisk_ctype="none"
 	ramdisk_loadline=""
 	ramdisk_entryline=""
@@ -261,7 +264,7 @@ EOF
 # $6 ... default flag
 fitimage_emit_section_config() {
 
-	conf_csum="sha1"
+	conf_csum="${FIT_HASH_ALG}"
 	if [ -n "${UBOOT_SIGN_ENABLE}" ] ; then
 		conf_sign_keyname="${UBOOT_SIGN_KEYNAME}"
 	fi