Do not enable DT_INIT_ARRAY/DT_FINI_ARRAY on uclinuxfdpiceabi
Commit r12-1328 enabled DT_INIT_ARRAY/DT_FINI_ARRAY for all Linux
targets, but this does not work for arm-none-uclinuxfdpiceabi: it
makes all the execution tests fail.
This patch restores the original behavior for uclinuxfdpiceabi.