armv8/ls2080: Remove workaround for erratum A008751

This errata a008751 is applied on Soc specific file currently.This will be
moved to a file where all the errata implementation will take place for usb
for fsl. This patch removes the errata workaround from soc specific file
for LS2080.

Signed-off-by: Sriram Dash <sriram.dash@nxp.com>
Signed-off-by: Rajesh Bhagat <rajesh.bhagat@nxp.com>