[CMake] cpack ppc64le rhel7.2 CPACK_RPM_PACKAGE_ARCHITECTURE

[M Kelly]

Hi,

I am working on an IBM Power8 RHEL7.2 system and we installed cmake 3.6
(default cmake from repo was 2.8.12?) but it seems when making a package
the arch is set incorrectly to x86_64 instead of ppc64le.

Anyone have a clue if this cpack on this dist could get its arch wrong ?
cmake 3.5.1 on Ubuntu works perfectly.

cmake --system-information does print the correct arch, so this happens only 
during rpm building.

thank you,
mark