Use GCC6 for all POWER8 platforms

(everything but Witherspoon)

We bring in P8 Hostboot patches from
https://github.com/open-power/hostboot/pull/62
as we wait for Hostboot development team to merge them.

Fixes: https://github.com/open-power/hostboot/issues/69
Fixes: https://github.com/open-power/hostboot/issues/61
Fixes: https://github.com/open-power/op-build/issues/355
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
diff --git a/openpower/configs/habanero_defconfig b/openpower/configs/habanero_defconfig
index 7cfad87..ca8fa57 100644
--- a/openpower/configs/habanero_defconfig
+++ b/openpower/configs/habanero_defconfig
@@ -3,6 +3,7 @@
 BR2_KERNEL_HEADERS_4_4=y
 BR2_BINUTILS_VERSION_2_26_X=y
 BR2_BINUTILS_EXTRA_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
+BR2_GCC_VERSION_6_X=y
 BR2_EXTRA_GCC_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
 BR2_TOOLCHAIN_BUILDROOT_CXX=y
 BR2_TARGET_GENERIC_HOSTNAME="skiroot"