Use pkg-config to find Qt 4 and 5 instead of direct qmake

The Qt Project recommendation is that there should always be a "qmake"
binary and it should never be renamed. If it's necessary to handle
multiple Qt versions, the Qt Project recommends using qtchooser.

Unfortunately, some distros do not follow the recommendation, so we
would need to check qmake-qt4, qmake-qt5, etc. So, instead, let's try
pkg-config.

Signed-off-by: Thiago Macieira <thiago.macieira@intel.com>
Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Michal Marek <mmarek@suse.com>

scripts/kconfig/Makefile

@@ -227,35 +227,24 @@ $(obj)/.tmp_qtcheck: $(src)/Makefile
 # Qt needs some extra effort...
 $(obj)/.tmp_qtcheck:
 	@set -e; $(kecho) "  CHECK   qt"; \
-	qtver=`qmake -query QT_VERSION` || { \
+	if pkg-config --exists Qt5Core; then \
+	    cflags="-std=c++11 -fPIC `pkg-config --cflags Qt5Core Qt5Gui Qt5Widgets`"; \
+	    libs=`pkg-config --libs Qt5Core Qt5Gui Qt5Widgets`; \
+	    moc=`pkg-config --variable=host_bins Qt5Core`/moc; \
+	elif pkg-config --exists QtCore; then \
+	    cflags=`pkg-config --cflags QtCore QtGui`; \
+	    libs=`pkg-config --libs QtCore QtGui`; \
+	    moc=`pkg-config --variable=moc_location QtCore`; \
+	else \
 	    echo >&2 "*"; \
-	    echo >&2 "* qmake failed."; \
+	    echo >&2 "* Could not find Qt via pkg-config."; \
+	    echo >&2 "* Please install either Qt 4.8 or 5.x. and make sure it's in PKG_CONFIG_PATH"; \
 	    echo >&2 "*"; \
 	    exit 1; \
-	}; \
-	qtlibdir=`qmake -query QT_INSTALL_LIBS`; \
-	qthdrdir=`qmake -query QT_INSTALL_HEADERS`; \
-	qtbindir=`qmake -query QT_INSTALL_BINS`; \
-	cflags="-I$$qthdrdir -I$$qthdrdir/QtCore -I$$qthdrdir/QtGui"; \
-	case "$$qtver" in \
-	5.*) \
-	    cflags="$$cflags -I$$qthdrdir/QtWidgets -std=c++11 -fPIC"; \
-	    libs="-L$$qtlibdir -lQt5Widgets -lQt5Gui -lQt5Core "; \
-	    ;; \
-	4.*) \
-	    libs="-L$$qtlibdir -lQtGui -lQtCore"; \
-	    ;; \
-	*) \
-	    echo >&2 "*"; \
-	    echo >&2 "* Found qmake but it is for Qt version $$qtver, which is not supported."; \
-	    echo >&2 "* Please install either Qt 4.8 or 5.x."; \
-	    echo >&2 "*"; \
-	    exit 1; \
-	    ;; \
-	esac; \
+	fi; \
 	echo "KC_QT_CFLAGS=$$cflags" > $@; \
 	echo "KC_QT_LIBS=$$libs" >> $@; \
-	echo "KC_QT_MOC=$$qtbindir/moc" >> $@
+	echo "KC_QT_MOC=$$moc" >> $@
 endif
 
 $(obj)/gconf.o: $(obj)/.tmp_gtkcheck