spapr: improve ibm,architecture-vec-5 property handling

spapr: improve ibm,architecture-vec-5 property handling

ibm,architecture-vec-5 is supposed to encode all option vector 5 bits
negotiated between platform/guest. Currently we hardcode this property
in the boot-time device tree to advertise a single negotiated
capability, "Form 1" NUMA Affinity, regardless of whether or not CAS
has been invoked or that capability has actually been negotiated.

Improve this by generating ibm,architecture-vec-5 based on the full
set of option vector 5 capabilities negotiated via CAS.

Signed-off-by: Michael Roth <[email protected]>
Signed-off-by: David Gibson <[email protected]>