clang-format: Make Qt includes matching case sensitive

Now that stable versions of all major distributions ship clang-format 12
or newer, we can use the CaseSensitive option for the Qt include
category. This fixes the problem that includes like

  #include <queue>

are put near the end.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

.clang-format

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 #
-# clang-format configuration file. Intended for clang-format >= 7.
+# clang-format configuration file. Intended for clang-format >= 12.
 #
 # For more information, see:
 #
@@ -75,6 +75,7 @@ IncludeCategories:
     Priority:        9
   # Qt includes (match before C++ standard library)
   - Regex:           '<Q([A-Za-z0-9\-_])+>'
+    CaseSensitive:   true
     Priority:        9
   # Headers in <> with an extension. (+system libraries)
   - Regex:           '<([A-Za-z0-9\-_])+\.h>'