ac/nir_to_llvm: move some interp defines to the header

These will be used in the following patch.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/amd/common/ac_nir_to_llvm.c

@@ -3976,10 +3976,6 @@ static LLVMValueRef visit_var_atomic(struct nir_to_llvm_context *ctx,
 	return result;
 }
 
-#define INTERP_CENTER 0
-#define INTERP_CENTROID 1
-#define INTERP_SAMPLE 2
-
 static LLVMValueRef lookup_interp_param(struct nir_to_llvm_context *ctx,
 					enum glsl_interp_mode interp, unsigned location)
 {

src/amd/common/ac_nir_to_llvm.h

@@ -118,6 +118,11 @@ enum ac_ud_index {
 	AC_UD_MAX_UD = AC_UD_TCS_MAX_UD,
 };
 
+/* Interpolation locations */
+#define INTERP_CENTER 0
+#define INTERP_CENTROID 1
+#define INTERP_SAMPLE 2
+
 /* descriptor index into scratch ring offsets */
 #define RING_SCRATCH 0
 #define RING_ESGS_VS 1