sparc64: update DAX submit to latest HV spec

sparc64: update DAX submit to latest HV spec

Orabug: 25927558

DAX submit needs to be updated to the latest HV spec. Along with a couple
small updates, the biggest modification is changing nomap_va to
status_data. This is mostly a cosmetic change but also adds support to
return the unavailable code via the exec ioctl. Further, augment the
comments and fix up a couple nits in the ccb submit hcall in hypervisor.h.

Signed-off-by: Jonathan Helman <jonathan.helman@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>