toolchain: kernel-headers: kernel Git tree mirror hash

Allow setting of mirror hash for Git kernel tree.

Signed-off-by: Petr Štetiar <ynezz@true.cz>
(cherry picked from commit 796d51834c5be85771d26e433fd509cd3bef72e3)

config/Config-devel.in

@@ -100,6 +100,11 @@ menuconfig DEVEL
 		  It can be a git hash or a branch name.
 		  If unused, the clone's repository HEAD will be checked-out.
 
+	config KERNEL_GIT_MIRROR_HASH
+		string "Enter hash of Git kernel tree source checkout tarball" if DEVEL
+		depends on (KERNEL_GIT_CLONE_URI != "")
+		default ""
+
 	config BUILD_LOG
 		bool "Enable log files during build process" if DEVEL
 		help

toolchain/kernel-headers/Makefile

@@ -21,6 +21,7 @@ ifneq ($(call qstrip,$(CONFIG_KERNEL_GIT_CLONE_URI)),)
   PKG_SOURCE_PROTO:=git
   PKG_SOURCE_URL:=$(call qstrip,$(CONFIG_KERNEL_GIT_CLONE_URI))
   PKG_SOURCE_VERSION:=$(call qstrip,$(CONFIG_KERNEL_GIT_REF))
+  PKG_MIRROR_HASH:=$(call qstrip,$(CONFIG_KERNEL_GIT_MIRROR_HASH))
 ifdef CHECK
   include $(INCLUDE_DIR)/kernel-version.mk
   PKG_VERSION:=$(LINUX_VERSION)