nitrogen6x_defconfig: bump u-boot / linux versions to current stable

As described on http://boundarydevices.com/u-boot-branches-for-i-mx6-april-2013/

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

configs/nitrogen6x_defconfig

@@ -12,13 +12,14 @@ BR2_TARGET_ROOTFS_EXT2=y
 
 # bootloader
 BR2_TARGET_UBOOT=y
-BR2_TARGET_UBOOT_BOARDNAME="mx6q_sabrelite"
+BR2_TARGET_UBOOT_BOARDNAME="nitrogen6q"
 BR2_TARGET_UBOOT_CUSTOM_TARBALL=y
-BR2_TARGET_UBOOT_CUSTOM_TARBALL_LOCATION="http://github.com/boundarydevices/u-boot-2009-08/tarball/1f7edab/u-boot-1f7edab.tar.gz"
+BR2_TARGET_UBOOT_CUSTOM_TARBALL_LOCATION="http://github.com/boundarydevices/u-boot-imx6/tarball/7176d07/u-boot-7176d07.tar.gz"
 
 # kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
 BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="http://github.com/boundarydevices/linux-imx6/tarball/5f84e92/linux-imx6-5f84e92.tar.gz"
+BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="http://github.com/boundarydevices/linux-imx6/tarball/2dc5560/linux-imx6-2dc5560.tar.gz"
 BR2_LINUX_KERNEL_DEFCONFIG="nitrogen6x"
 BR2_LINUX_KERNEL_INSTALL_TARGET=y