cups: fix static linking problem

In static linking configurations, cups fails to build due to the lack of
Scrt1.o from uClibc toolchains. This Scrt1.o is only needed for PIE
binaries. Since we don't really care about PIE binaries in the context
of Buildroot, this commit solves the problem by patching cups to not
generate a PIE binary.

Fixes:

  http://autobuild.buildroot.net/results/445a401da2f63a6c43d7c166516287db6cc977ab/



Cc: Olivier Schonken <olivier.schonken@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>