drm/amd/display: fixup DML dependencies

[why]
Need to fix DML portability issues to enable SW unit testing around DML

[how]
Move calcs into dc include folder since multiple components reference it
Remove relative paths to external dependencies
Signed-off-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dml_common_defs.c

@@ -24,7 +24,7 @@
  */
 
 #include "dml_common_defs.h"
-#include "../calcs/dcn_calc_math.h"
+#include "dcn_calc_math.h"
 
 #include "dml_inline_defs.h"
 

drivers/gpu/drm/amd/display/dc/dml/dml_inline_defs.h

@@ -27,7 +27,7 @@
 #define __DML_INLINE_DEFS_H__
 
 #include "dml_common_defs.h"
-#include "../calcs/dcn_calc_math.h"
+#include "dcn_calc_math.h"
 #include "dml_logger.h"
 
 static inline double dml_min(double a, double b)