kernel modules: use FREETZ_KERNEL_VERSION_2_6_28 instead of 7390 \(7340 has 2.6.28 too and uses 7390's sources\)

git-svn-id: file:///var/svn/freetz/trunk@10237 149334a1-2f27-0410-a3b9-fc62619ac1e6
fix (kernel module related) unmet dependency

git-svn-id: file:///var/svn/freetz/trunk@10238 149334a1-2f27-0410-a3b9-fc62619ac1e6