mtip32xx: Increase timeout for STANDBY IMMEDIATE command

Increased timeout for STANDBY IMMEDIATE command to 2 minutes.

Signed-off-by: Selvan Mani <smani@micron.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>