pandaboard: fix defconf build with recent kernels

The patch "pandaboard: Fix defconfig build" locked the
default pandaboard kernel to 3.8.11. This is inconvenient,
since the boot process has changed since kernel > 3.8.

Update the default kernel to 3.12.2 and fix the boot image
configuration, but remain compatible with legacy U-Boot
versions by using appended flattened device tree uImage.

This change *should* keep future kernels compatible with a
fixed U-Boot version.

Note the default device tree is now for the pandaboard-ES,
so users of other board revisions will need to set the
correct DTS_NAME.

[Peter: use custom kernel headers version (3.12.2)]
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/pandaboard_defconfig

@@ -11,14 +11,21 @@ BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS=y
 BR2_TARGET_ROOTFS_EXT2=y
 # BR2_TARGET_ROOTFS_TAR is not set
 
-# Lock to 3.8 headers to avoid breaking with newer kernels
-BR2_KERNEL_HEADERS_3_8=y
+# Lock to 3.12 headers to avoid breaking with newer kernels
+BR2_KERNEL_HEADERS_VERSION=y
+BR2_DEFAULT_KERNEL_VERSION="3.12.2"
 
 # Kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="3.8.11"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="3.12.2"
 BR2_LINUX_KERNEL_DEFCONFIG="omap2plus"
+BR2_LINUX_KERNEL_UIMAGE_LOADADDR="0x80008000"
+BR2_LINUX_KERNEL_APPENDED_UIMAGE=y
+BR2_LINUX_KERNEL_APPENDED_DTB=y
+BR2_LINUX_KERNEL_USE_INTREE_DTS=y
+# might need omap4-panda or omap4-panda-a4 instead
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="omap4-panda-es"
 
 # GCC
 BR2_GCC_VERSION_4_6_X=y
@@ -29,3 +36,6 @@ BR2_TARGET_UBOOT_FORMAT_IMG=y
 BR2_TARGET_UBOOT_BOARDNAME="omap4_panda"
 BR2_TARGET_UBOOT_SPL=y
 BR2_TARGET_UBOOT_SPL_NAME="MLO"
+BR2_TARGET_UBOOT_LATEST_VERSION=n
+BR2_TARGET_UBOOT_CUSTOM_VERSION=y
+BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2012.07"