ioc4: automatically load sgiioc4 subordinate module

Modify ioc4 to always load the sgiioc4 IDE module if the board carrying
the IOC4 hardware actually implements the IDE interface (not all boards
bring this functionality off the IOC4 chip).  A drive hosted on the IDE
interface may contain the root filesystem, and sgiioc4 doesn't load
automatically as ioc4 owns the PCI device ID, not sgiioc4.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Michael Reed <mdr@sgi.com>
Signed-off-by: Brent Casavant <bcasavan@sgi.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>