[SCSI] drivers/base/bus.c - export reprobe

Adding support for exposing hidden raid components for sg
interface. The sdev->no_uld_attach flag will set set accordingly.

The sas module supports adding/removing raid volumes using online
storage management application interface.

This patch was provided to me by Christoph Hellwig.

Signed-off-by: Eric Moore <Eric.Moore@lsil.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>