checkpatch: check for SPDX tags of licenses in use

Fix the patch of the external helper spdxcheck.py accordingly to
OpenOCD folder structure.
List only the current LICENSES subfolders in spdxcheck.py .
Enable the check for SPDX headers.
Extend the check for TCL and Makefile.am files.

Change-Id: I0a40da0127746217ee0ac416058d5ceb922428ff
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/5608
Tested-by: jenkins

.checkpatch.conf

@@ -23,7 +23,6 @@
 --ignore PREFER_DEFINED_ATTRIBUTE_MACRO
 --ignore PREFER_FALLTHROUGH
 --ignore PREFER_KERNEL_TYPES
---ignore SPDX_LICENSE_TAG
 --ignore SPLIT_STRING
 --ignore SSCANF_TO_KSTRTO
 --ignore SWITCH_CASE_INDENT_LEVEL

tools/scripts/checkpatch.pl

@@ -1132,10 +1132,12 @@ sub is_maintained_obsolete {
 sub is_SPDX_License_valid {
 	my ($license) = @_;
 
-	return 1 if (!$tree || which("python3") eq "" || !(-x "$root/scripts/spdxcheck.py") || !(-e "$gitroot"));
+	# OpenOCD specific: Begin: replace s"scripts"tools/scripts"
+	return 1 if (!$tree || which("python3") eq "" || !(-x "$root/tools/scripts/spdxcheck.py") || !(-e "$gitroot"));
 
 	my $root_path = abs_path($root);
-	my $status = `cd "$root_path"; echo "$license" | scripts/spdxcheck.py -`;
+	my $status = `cd "$root_path"; echo "$license" | tools/scripts/spdxcheck.py -`;
+	# OpenOCD specific: End
 	return 0 if ($status ne "");
 	return 1;
 }
@@ -3669,6 +3671,10 @@ sub process {
 					$comment = '#';
 				} elsif ($realfile =~ /\.rst$/) {
 					$comment = '..';
+				# OpenOCD specific: Begin
+				} elsif ($realfile =~ /\.(am|cfg|tcl)$/) {
+					$comment = '#';
+				# OpenOCD specific: End
 				}
 
 # check SPDX comment style for .[chsS] files

tools/scripts/spdxcheck.py

@@ -49,7 +49,9 @@ def read_spdxdata(repo):
 
     # The subdirectories of LICENSES in the kernel source
     # Note: exceptions needs to be parsed as last directory.
-    license_dirs = [ "preferred", "dual", "deprecated", "exceptions" ]
+    # OpenOCD specific: Begin
+    license_dirs = [ "preferred", "stand-alone", "exceptions" ]
+    # OpenOCD specific: End
     lictree = repo.head.commit.tree['LICENSES']
 
     spdx = SPDXdata()