cmake: add patch to fix FindQt4 issue

The FindQt4 module of CMake insists on having uic, even if the QtGui
module isn't part of the requirements to build the program. This isn't
correct, as Qt doesn't build/install the uic program when QtGui is
disabled (uic is used to generate some UI code).

This has been fixed upstream in
http://cmake.org/gitweb?p=cmake.git;a=commit;h=43cb9b8276a70d153d56a69d5c61daaf2bc51b78

. This
commit will be part of the upcoming 2.8.4 CMake release, but in the
mean time, let's include it in Buildroot.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>