Audio: DCblock: Fix search path to common functions

A function dcblock_paths.m is added to handle add and remove
of path.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

src/audio/dcblock/tune/dcblock_paths.m

@@ -0,0 +1,18 @@
+function dcblock_paths(enable)
+
+% dcblock_paths(enable)
+% enable - set to true to enable needed search path
+%          set to false to disable the search paths
+%
+
+% SPDX-License-Identifier: BSD-3-Clause
+%
+% Copyright (c) 2024, Intel Corporation. All rights reserved.
+
+	common = '../../../../tools/tune/common';
+	if enable
+		addpath(common);
+	else
+		rmpath(common);
+	end
+end

src/audio/dcblock/tune/example_dcblock.m

@@ -49,7 +49,7 @@ function dcblock_blob_calculate(prm)
 	R_coeffs = R * ones(1, channels);
 end
 
-addpath ./../common
+dcblock_paths(true);
 
 blob8 = dcblock_build_blob(R_coeffs, endian);
 blob8_ipc4 = dcblock_build_blob(R_coeffs, endian, 4);
@@ -74,7 +74,7 @@ function dcblock_blob_calculate(prm)
 figure
 dcblock_plot_stepfn(R_coeffs(1), fs);
 
-rmpath ./../common
+dcblock_paths(false);
 
 end