Fixed build of generic linuxinput plugin.

Change-Id: I2289e369c831bfee9646ffe5c587647443548804
Reviewed-on: http://codereview.qt.nokia.com/1870
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Jørgen Lind <jorgen.lind@nokia.com>

src/plugins/generic/linuxinput/linuxinput.pro

@@ -9,6 +9,8 @@ DEFINES += QT_QWS_KBD_LINUXINPUT
 
 HEADERS	= qlinuxinput.h
 
+QT += core-private
+
 SOURCES	= main.cpp \
 	qlinuxinput.cpp