Add a configuration specific C header generator

[jordancarlin]

ACT 4.0 is using UDB as its main configuration engine, and one of the inputs that is needed for the tests is a C header that gives the value of each parameter and lists which extensions are included. This file will be included in the assembly tests so that parts of the tests can be dependent on parameters.

We have been handwriting these files for early testing of the framework, but all of the information needed for them is in the UDB config, so it should be possible to generate them instead. I've included an example snippet from a file below.

// Extensions
#define F_SUPPORTED
#define ZICSR_SUPPORTED
...

// Parameters
#define MXLEN 64
#define PMP_GRANULARITY 4
#define NUM_PMP_ENTRIES 16

[jordancarlin]

@ThinkOpenly We discussed this last week, and I know it's a bit late at this point, but if one of the mentees was still looking for another generator, I think this should be a fairly straightforward one.