Add test for Khronos Group license and whitelist it.

third_party/devscripts/licensecheck.pl

Index: third_party/devscripts/licensecheck.pl
diff --git a/third_party/devscripts/licensecheck.pl b/third_party/devscripts/licensecheck.pl
index bd60603ee564952f83c5f7e0d2253c77bd875056..acc21306828df38dddfeb8fed8edcba32e7009bc 100755
--- a/third_party/devscripts/licensecheck.pl
+++ b/third_party/devscripts/licensecheck.pl
@@ -577,6 +577,10 @@ sub parselicense($) {
         $license = $license . "with libtool exception";
     }
 
+    if ($licensetext =~ /These materials are protected by copyright laws and contain material proprietary to the Khronos Group, Inc\. You may use these materials for implementing Khronos specifications, without altering or removing any trademark, copyright or other notice from the specification/) {
+        $license = $license . "Khronos Group";
+    }
+
     $license = "UNKNOWN" if (!length($license));
 
     # Remove trailing spaces.