Register the compute device as an accel device, and remove the creation
of the habanalabs compute char device.

The IOCTLs in this patch are still handled by the current driver
handler. Moving to DRM IOCTL handling requires moving the IOCTLs
numbers to a specific range, so it will be handled in subsequent
patches.
Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>