grub-efi: Add xen_boot support when 'xen' is in DISTRO_FEATURES for aarch64

'xen-boot' module is available only for aarch64.

(From OE-Core rev: bfabc6d4f8742cc1fdeb49c180b0f78faf5739a2)

Signed-off-by: Kamil Dziezyk <kamil.dziezyk@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-bsp/grub/grub-efi_2.06.bb

@@ -73,6 +73,9 @@ do_install() {
 GRUB_BUILDIN ?= "boot linux ext2 fat serial part_msdos part_gpt normal \
                  efi_gop iso9660 configfile search loadenv test"
 
+# 'xen_boot' is a module valid only for aarch64
+GRUB_BUILDIN:append:aarch64 = "${@bb.utils.contains('DISTRO_FEATURES', 'xen', ' xen_boot', '', d)}"
+
 do_deploy() {
 	install -m 644 ${B}/${GRUB_IMAGE_PREFIX}${GRUB_IMAGE} ${DEPLOYDIR}
 }