buildroot: Move to 2015.11.1 release

The November 2015 buildroot release incroperates more of our patches,
further reducing the delta between what we require for openpower and
upstream.

 - Update defconfigs.
   * The Chelsio T4 option BR2_PACKAGE_LINUX_FIRMWARE_CXGB4
     has been renamed to BR2_PACKAGE_LINUX_FIRMWARE_CXGB4_T4 to
     better account for the fact that a T5 variant exists.
   * Explictly set kernel version to the same as used for GCC headers,
     and set headers version to 4.2.6.

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/garrison_defconfig b/openpower/configs/garrison_defconfig
index cd74454..e13fcf1 100644
--- a/openpower/configs/garrison_defconfig
+++ b/openpower/configs/garrison_defconfig
@@ -45,8 +45,9 @@
 BR2_ROOTFS_DEVICE_TABLE="../openpower/device_table.txt"
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var"
 BR2_LINUX_KERNEL=y
-BR2_LINUX_KERNEL_VERSION="4.2.6"
+BR2_LINUX_KERNEL_SAME_AS_HEADERS=y
 BR2_KERNEL_HEADERS_4_2=y
+BR2_DEFAULT_KERNEL_HEADERS="4.2.6"
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL)/linux"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL)/configs/linux/skiroot_defconfig"
@@ -54,7 +55,7 @@
 BR2_PACKAGE_BUSYBOX_SHOW_OTHERS=y
 BR2_PACKAGE_LINUX_FIRMWARE=y
 BR2_PACKAGE_LINUX_FIRMWARE_BNX2X=y
-BR2_PACKAGE_LINUX_FIRMWARE_CXGB4=y
+BR2_PACKAGE_LINUX_FIRMWARE_CXGB4_T4=y
 BR2_PACKAGE_I2C_TOOLS=y
 BR2_PACKAGE_NCURSES_WCHAR=y
 BR2_PACKAGE_DROPBEAR=y