perf tools: Remove sys/ioctl.h from util.h

Not needed in this header, added to the places that need 'struct
winsize' and the ioctl defines.

Link: http://lkml.kernel.org/n/tip-2pznlli3146y4242otlcm70m@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>