[SCSI] ipr: Add support to flash FPGA and flash back DRAM images

The write buffer command is used to download and burn new IOA FW images.
The same interface can now be used to flash FPGA and flash back DRAM images.
To download and flash the new images takes more than 15 minutes, so increase
the write buffer command timeout to 30 minutes.

The FPGA and flash back DRAM images don't have the same card_type as the IOA FW
image. So, remove the sanity checking from the driver.  The adapter has sanity
checking and will only accept a valid image.

Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>