intel/common: provide common ioctl routine

intel/common: provide common ioctl routine

i965 links against libdrm for drmIoctl, but anv and iris both
re-implement this routine to avoid the dependency.

intel/dev also needs an ioctl wrapper, so lets share the same
implementation everywhere.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>