configs: Update garrison to use a le build

Fixes https://github.com/open-power/op-build/issues/216

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/openpower/configs/garrison_defconfig b/openpower/configs/garrison_defconfig
index c5bde78..3069ac7 100644
--- a/openpower/configs/garrison_defconfig
+++ b/openpower/configs/garrison_defconfig
@@ -1,7 +1,10 @@
-BR2_powerpc64=y
+BR2_powerpc64le=y
 BR2_powerpc_power8=y
 BR2_OPENPOWER_PLATFORM=y
 
+BR2_BINUTILS_EXTRA_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
+BR2_EXTRA_GCC_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
+
 BR2_OPENPOWER_CONFIG_NAME="garrison"
 BR2_OPENPOWER_XML_PACKAGE="garrison-xml"
 BR2_HOSTBOOT_CONFIG_FILE="garrison.config"