msm8226: Enable authentication of the kernel image.

Generates a kernel image with signed hash which will be
verified by the bootloader.

Change-Id: I953cecbf6ede4733e95cf689d4c8dba2d129bc58
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 79bb467..39da623 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -41,6 +41,8 @@
 BOARD_KERNEL_TAGS_OFFSET := 0x01E00000
 BOARD_RAMDISK_OFFSET     := 0x02000000
 
+TARGET_BOOTIMG_SIGNED := true
+
 # Shader cache config options
 # Maximum size of the  GLES Shaders that can be cached for reuse.
 # Increase the size if shaders of size greater than 12KB are used.