qt5webkit: needs host-flex

Fixes http://autobuild.buildroot.net/results/dbe/dbe4e8f7b7ddd8ab3fdc1a6f41d775b3c8132160/

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/qt5/qt5webkit/qt5webkit.mk

@@ -7,7 +7,7 @@
 QT5WEBKIT_VERSION = $(QT5_VERSION)
 QT5WEBKIT_SITE = $(QT5_SITE)
 QT5WEBKIT_SOURCE = qtwebkit-opensource-src-$(QT5WEBKIT_VERSION).tar.xz
-QT5WEBKIT_DEPENDENCIES = qt5base sqlite host-ruby host-gperf host-bison
+QT5WEBKIT_DEPENDENCIES = qt5base sqlite host-ruby host-gperf host-bison host-flex
 QT5WEBKIT_INSTALL_STAGING = YES
 
 ifeq ($(BR2_PACKAGE_QT5BASE_LICENSE_APPROVED),y)