[SCSI] ipr: increase dump size in ipr driver

To help debugging several new SAS controllers, increase the dump size in ipr
driver to 80MB.

Signed-off-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>