The earlier commit 8d9273918635f0301368c01b56c03a6f339e8d51
(Consolidate early console and PPCDBG code) broke iSeries because
it caused unregister_console(&udbg_console) to be called
unconditionally. iSeries never registers the udbg_console.
This just reverts part of the change.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
38c0ff06d5