Added dt_on_output field to auxinfo_t.

Details:
- Added a new field to the auxinfo_t struct that can be used, in theory,
  to request type conversion before the microkernel stores/accumulates
  its microtile back to memory.
- Added the appropriate get/set static functions to bli_type_defs.h.

frame/include/bli_type_defs.h

@@ -998,6 +998,9 @@ typedef struct
 	inc_t  is_a;
 	inc_t  is_b;
 
+	// The type to convert to on output.
+	num_t  dt_on_output;
+
 } auxinfo_t;