drm: Fix ioc32 compat layer

Previously any ioctls that weren't explicitly listed in the compat ioctl
table would fail with ENOTTY.  If the incoming ioctl number is outside the
range of the table, assume that it Just Works, and pass it off to drm_ioctl.
This make the fence related ioctls work on 64-bit PowerPC.

Signed-off-by: Dave Airlie <airlied@linux.ie>