linux-phytec-fsl

cxl: Document external user of existing API

Now that libcxl is public, let's document it.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>