Add support for setting cpu value for anal module

Now, anal has it's own `anal.cpu` config value. It can be used to
support multiple CPUs handled by one analysis module.
TMS320: add on-the-fly cpu changing ability

Add support for changing CPU by looking at `asm.cpu` variable
TMS320: move c55plus under the TMS320 namespace

Sorry for the huge patch, but there is nothing special. We just move
asm/arch/c55plus into the asm/arch/tms320 and add some wrappers to use
existing code base under the new namespace.

Also, we've implement TMS320 anal module that supports now c55+ only. To
be continued...
TMS320: finally update README.md
Merge branch 'dev-c55plus' of https://github.com/milabs/radare2 into pullreq