MIPS DSP configure detection and initial blend optimizations.

MIPS DSP configure detection and initial blend optimizations.

Adds new MIPS configure test and -no-mips_dsp and -no-mips_dspr2
configure options.

List of optimized implementations:

- comp_func_SourceOver
- comp_func_Source
- qt_memfill32
- qt_destFetchARGB32
- qt_destStoreARGB32
- blend [RGB32][RGB32]
- blend [ARGB32_Pre][RGB32]
- blend [RGB32][ARGB32_Pre]
- blend [ARGB32_Pre][ARGB32_Pre]

Change-Id: I35411858295b7b3f4895eb56e3b93397528903cc
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>