cxl: Enable PCI device ID for future IBM CXL adapter

Add support for future IBM Coherent Accelerator (CXL) device
with ID of 0x0601.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>