[POWERPC] EEH: Power4 systems sometimes need multiple resets.

On detection of an EEH error, some Power4 systems seem to occasionally
want to be reset twice before they report themselves as fully recovered.
This patch re-arranges the code to attempt additional resets if the first
one doesn't take.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>