package/qhull: add dependency on gcc >= 4.4

A variadic template template parameters [1] is used in QhullSet.h, this require
a toolchain with (at least) gcc 4.4 [2][3].

Fixes (bfin toolchain with gcc 4.3):
http://autobuild.buildroot.net/results/32f/32f324c7920ac46d393954de13b8a98a77a0c392

[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2555.pdf
[2] https://gcc.gnu.org/gcc-4.3/cxx0x_status.html
[3] https://gcc.gnu.org/gcc-4.4/cxx0x_status.html



Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>