Disable CMake Package Registry when required.

If the CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY or
CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY variables are set, pass
NO_CMAKE_PACKAGE_REGISTRY and/or NO_CMAKE_SYSTEM_PACKAGE_REGISTRY to all
the find_package() calls.

Starting from CMake 3.1 this is done automatically, so there is no need
to explicitly pass the arguments.

This is a workaround for CMake bug #14849