Enable p8-pore-binutils as an external toolchain

Create the infrastructure necessary to bundle the p8-pore-binutils as
part of the sdk build, allowing it to be re-inserted as part of an
external sdk.

Signed-off-by: Klaus Heinrich Kiwi <klaus@linux.vnet.ibm.com>
diff --git a/openpower/toolchain/p8-pore-toolchain/p8-pore-toolchain.mk b/openpower/toolchain/p8-pore-toolchain/p8-pore-toolchain.mk
index b618004..7936be5 100644
--- a/openpower/toolchain/p8-pore-toolchain/p8-pore-toolchain.mk
+++ b/openpower/toolchain/p8-pore-toolchain/p8-pore-toolchain.mk
@@ -3,5 +3,7 @@
 # p8-pore-toolchain
 #
 ################################################################################
+P8_PORE_TOOLCHAIN_DIR = $(STAGING_SUBDIR)/p8-pore-toolchain
+P8_PORE_TOOLCHAIN_BIN = $(STAGING_SUBDIR)/p8-pore-toolchain/linux
 
 $(eval $(host-virtual-package))