[SPARC64]: Fix central/FHC bus handling on Ex000 systems.
1) probe_other_fhcs() wants to see only non-central FHC busses, so skip FHCs that don't sit off the root 2) Like SBUS, FHC can lack the appropriate address and size cell count properties, so add an of_busses entry and handlers for that. 3) Central FHC irq translator probing was buggy. We were trying to use dp->child in irq_trans_init but that linkage is not setup at this point. So instead, pass in the parent of "dp" and look for the child "fhc" with parent "central". Thanks to the tireless assistence of Ben Collins in tracking down these problems and testing out these fixes. Signed-off-by: David S. Miller <email@example.com>