Revert "libcdio: disable on ARC, triggers a toolchain bug"

This reverts commit 459f7302.

libcdio building is fixed for ARC in
2b360bd5 "gcc: arc-2017.03-rc2: Fix "unrecognized supposed constant" error"

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Tested-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>