libgpg-error: Support build for native on ppc64/ppc64le hosts

Both RHEL and SLES uses ppc64/ppc64le for powerpc 64 bit big/little endian targets instead of powerpc64/powerpc64le in libgpg-error.

Also libgpg-error provides common target system names in form like <arch>-unknown-linux-gnu.

Add mapping for ppc64/ppc64le targets to their libgpg-error equivalents to fix native builds.

Cross build for arm64 tested on IBM Power 8 machine with RHEL7 for ppc64le variant only, but should work for ppc64 as well.

---
 meta/recipes-support/libgpg-error/libgpg-error_1.32.bb | 2 ++
 1 file changed, 2 insertions(+)

v2:
Make thinkgs explicit:

    ppc64   -> powerpc64-unknown-linux-gnu
    ppc64le -> powerpc64le-unknown-linux

index 4f3e3d8..7655106 100644
@@ -48,6 +48,8 @@ do_compile_prepend() {
 	  mips*el)    TUPLE=mipsel-unknown-linux-gnu ;;
 	  mips*)      TUPLE=mips-unknown-linux-gnu ;;
 	  x86_64)     TUPLE=x86_64-unknown-linux-gnu ;;
+	  ppc64)      TUPLE=powerpc64-unknown-linux-gnu ;;
+	  ppc64le)    TUPLE=powerpc64le-unknown-linux-gnu ;;
 	  *)          TUPLE=${TARGET_ARCH}-unknown-linux-gnu ;;
 	esac
 

2.7.4