MdePkg IndustryStandard/Scsi.h: Add Unmap command support
According to the SCSI Block Commands - 4 (SBC-4) spec, the patch add SCSI
unmap command support in IndustryStandard/Scsi.h.
The following changes have been made:
1. Add SCSI unmap command OP Code
2. Update the structure definition for Block Limits VPD page
3. Add structure definitions for UNMAP parameter list header & UNMAP block
descriptor.