Enable OpenCL and OpenMP support for john --jumbo

This enables OpenCL and OpenMP support in John the Ripper, if it is compiled with the jumbo patch.

Clang does not currently support OpenMP, so when building with clang OpenMP is disabled.
Looking at other formulas the same applies to Leopard.

The OpenMP-enabled formats will be used automatically, while for OpenCL you need to specify the specific `-opencl` suffixed format. Use `john --list=formats` to see what's available.