MdeModulePkg/PartitionDxe: Fixed El Torito support when the medium is not a CDROM

MdeModulePkg/PartitionDxe: Fixed El Torito support when the medium is not a CDROM

El Torito format can be used on different media (eg: USB).
A ISO image can be dumped onto a USB mass-storage.

These media might not have the same block size as the CDROM media (ie: 2KB).
The El Torito code and the specification assumes a LBA 2KB.

In addition, the specification says in "12.3.4.4 CD-ROM and DVD-ROM":
UEFI code does not assume a fixed block size.

I was able to dupliacte the issue by copying a debian ISO on a USB driver.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16600 6f19259b-4bc3-4df7-8a09-765794883524