contrib: qt4: fix build in 32-bit chroot with 64-bit kernel

contrib/src/qt4/chroot.patch

+Fix build when using a 32-bit chroot with a x86_64 kernel
+Native tools would be built with -m64
+--- qt-everywhere-opensource-src-4.7.4/configure.orig	2011-11-11 14:48:12.944666802 -0500
++++ qt-everywhere-opensource-src-4.7.4/configure	2011-11-11 14:48:55.108875882 -0500
+@@ -168,7 +168,7 @@
+ #-------------------------------------------------------------------------------
+ 
+ # need that throughout the script
+-UNAME_MACHINE=`(uname -m) 2>/dev/null` || UNAME_MACHINE=unknown
++UNAME_MACHINE=`(gcc -dumpmachine|cut -d- -f1) 2>/dev/null` || UNAME_MACHINE=unknown
+ UNAME_RELEASE=`(uname -r) 2>/dev/null` || UNAME_RELEASE=unknown
+ UNAME_SYSTEM=`(uname -s) 2>/dev/null`  || UNAME_SYSTEM=unknown
+ UNAME_VERSION=`(uname -v) 2>/dev/null` || UNAME_VERSION=unknown

contrib/src/qt4/rules.mak

@@ -21,6 +21,7 @@ qt4: qt-$(QT4_VERSION).tar.gz .sum-qt4
 	$(UNPACK)
 	patch -p0 < $(SRC)/qt4/cross.patch
 	patch -p0 < $(SRC)/qt4/styles.patch
+	patch -p0 < $(SRC)/qt4/chroot.patch
 	patch -p0 < $(SRC)/qt4/imageformats.patch
 	mv qt-everywhere-opensource-src-4.7.4 $@ && touch $@