Improve TQt detection. Use CFLAGS from pkg-config

instead of hard-coded include paths.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 3bdc9fd55f)

acinclude.m4.in

@@ -1084,10 +1084,11 @@ AC_DEFUN([KDE_USE_TQT],
   kde_tqtver=0
   kde_tqtsubver=0
 
+  KDE_PKG_CHECK_MODULES(TQt, tqt)
   AC_LANG_SAVE
   AC_LANG_CPLUSPLUS
   ac_cxxflags_safe="$CXXFLAGS"
-  CXXFLAGS="$CXXFLAGS -I/usr/include/tqt -I/usr/include/tqt3"
+  CXXFLAGS="$CXXFLAGS $TQt_CFLAGS"
   AC_TRY_COMPILE([
   #include <tqt.h>
   ], ,