refactor(plat/zynqmp): optimize the code to save some space

As there is constraint with the space for the release builds,
remove some of the legacy code.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Change-Id: I5b8b16f34ed8e480f16ab1aeac80b85cdb391852
3 files changed