cxl: Set the valid bit in PE for dedicated mode

Make sure to set the valid-bit in software-state field of the
populated PE. This was earlier missing for dedicated mode AFUs, hence
was causing a PSL freeze when the AFU was activated.

Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>