MdeModulePkg/ScsiDisk: Increase the value of SCSI_DISK_TIMEOUT to 30s

As ScsiDisk and ScsiBus driver are used to manage SCSI or ATAPI devices,
the timeout value is updated to 30s to follow ATA/ATAPI spec in which
the device may take up to 30s to respond command.

The change is used to solve device compatibility issue found with a TEAC
DV-W28S-WZ3 slim DVD plus a SONY AccuCORE DVD-R media in which the DVD
spends 8s to response READ_CAPACITY cmd after resetting the host machine.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19612 6f19259b-4bc3-4df7-8a09-765794883524