payloads: Update GRUB2 stable version from 2.04 to 2.06

GRUB2 was released on June 8th, 2021 [1].

[1]: https://lists.gnu.org/archive/html/grub-devel/2021-06/msg00022.html

Change-Id: I050a78c769c3cd4c9ae627c7e3124a4894a018d7
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55343
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
diff --git a/payloads/external/GRUB2/Kconfig b/payloads/external/GRUB2/Kconfig
index 67499c6..e41c562 100644
--- a/payloads/external/GRUB2/Kconfig
+++ b/payloads/external/GRUB2/Kconfig
@@ -15,7 +15,7 @@
 	default GRUB2_STABLE
 
 config GRUB2_STABLE
-	bool "2.04"
+	bool "2.06"
 	help
 	  Stable GRUB2 version
 
diff --git a/payloads/external/GRUB2/Makefile b/payloads/external/GRUB2/Makefile
index 5e82f3e..1691e9b 100644
--- a/payloads/external/GRUB2/Makefile
+++ b/payloads/external/GRUB2/Makefile
@@ -1,9 +1,9 @@
 TAG-$(CONFIG_GRUB2_MASTER)=origin/HEAD
 TAG-$(CONFIG_GRUB2_REVISION)=$(CONFIG_GRUB2_REVISION_ID)
-TAG-$(CONFIG_GRUB2_STABLE)=grub-2.04
+TAG-$(CONFIG_GRUB2_STABLE)=grub-2.06
 NAME-$(CONFIG_GRUB2_MASTER)=HEAD
 NAME-$(CONFIG_GRUB2_REVISION)=$(CONFIG_GRUB2_REVISION_ID)
-NAME-$(CONFIG_GRUB2_STABLE)=2.04
+NAME-$(CONFIG_GRUB2_STABLE)=2.06
 
 project_git_repo=https://git.savannah.gnu.org/git/grub.git/
 project_dir=grub2