mesa/formatquery: Added COLOR_ENCODING <pname> query.
mesa/formatquery: Added COLOR_ENCODING <pname> query.

From the ARB_internalformat_query2 specification:

   "- COLOR_ENCODING: The color encoding for the resource is returned in
      <params>.  Possible values for color buffers are LINEAR or SRGB,
      for linear or sRGB-encoded color components, respectively. For non-color
      formats (such as depth or stencil), or for unsupported resources,
      the value NONE is returned."

Reviewed-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler