VITIS-12786 - Fetch scratch-pad-mem size from elf

[dezhiAmd]

Problem solved by the commit

scratch-pad-mem is a bo used to store L2 memory for the purpose of preemption. Currently scratch-pad-mem size is hardcoded instead of read from elf file

Bug / issue (if any) fixed, which PR introduced the bug, how it was discovered

How problem was solved, alternative solutions (if any) and why they were rejected

scratch-pad-mem size is encoded into the elf file by assembler. Refer to https://gitenterprise.xilinx.com/XRT/aiebu/pull/65/. This PR parse the scratch-pad-mem size from the elf file.

Risks (if any) associated the changes in the commit

What has been tested and how, request additional testing if necessary

Documentation impact (if any)