Rename some CPU_MIPSxxx options and add new CPU_MIPSxxx options

Rename some CPU_MIPSxxx options and add new CPU_MIPSxxx options

This revision does the following renames:
CPU_MIPS24KC -> CPU_MIPS24K
CPU_MIPS74KC -> CPU_MIPS74K
CPU_MIPS1004KC -> CPU_MIPS1004K

It also adds the following new CPU_MIPSxxx options:
CPU_MIPS24KE, CPU_MIPS34K, CPU_MIPS1074K, CPU_INTERAPTIV, CPU_PROAPTIV

CPU_MIPSxxxxKC is limiting and possibly misleading as it implies the
MIPSxxxxK CPU has no FPU.
It would be better if the CPUs are named after their standard functionalities
only and the presence or absence of FPU can then be controlled via the
CPU_HAVEFPU option.

I will send out another dependent revision that moves MIPS 32 r2 and r3
CPUs to use the EHB instruction for clearing hazards instead of NOP/SSNOP.

Submitted by:	Stanislav Galabov <sgalabov@gmail.com>
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D5077