[PATCH v2] checkpatch: add missing bindings license check

[Dmitry Rokosov]

All headers from 'include/dt-bindings/' must be verified by checkpatch
together with Documentation bindings, because all of them are part of
the whole DT bindings system.

The requirement is dual licensed and matching pattern:
    /GPL-2\.0(?:-only|-or-later|\+)? (?:OR|or) BSD-2-Clause/

The issue was found during patch review:
https://lore.kernel.org/all/20230313201259.19998-4-ddrokosov@xxxxxxxxxxxxxx/

Signed-off-by: Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxx>
---
Changes v2 since v1 at [1]:
    - include/dt-bindings check is aligned to open parens
    - introduce more strict pattern for bindings license:
      /GPL-2\.0(?:-only|-or-later|\+)? (?:OR|or) BSD-2-Clause/

Links:
    [1] https://lore.kernel.org/all/20230317201621.15518-1-ddrokosov@xxxxxxxxxxxxxx/
---
 scripts/checkpatch.pl | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 78cc595b98ce..de669d29f60c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3709,8 +3709,9 @@ sub process {
 						WARN("SPDX_LICENSE_TAG",
 						     "'$spdx_license' is not supported in LICENSES/...\n" . $herecurr);
 					}
-					if ($realfile =~ m@^Documentation/devicetree/bindings/@ &&
-					    not $spdx_license =~ /GPL-2\.0.*BSD-2-Clause/) {
+					if (($realfile =~ m@^Documentation/devicetree/bindings/@ ||
+					     $realfile =~ m@^include/dt-bindings/@) &&
+					    not $spdx_license =~ /GPL-2\.0(?:-only|-or-later|\+)? (?:OR|or) BSD-2-Clause/) {
 						my $msg_level = \&WARN;
 						$msg_level = \&CHK if ($file);
 						if (&{$msg_level}("SPDX_LICENSE_TAG",
-- 
2.36.0