edac: cortex: Remove CTI PMU workaround

CTI PMU workaround is no longer needed for latest targets.
It was only intended for the MSM8994v1 target.

Change-Id: I6b906f4033d5d0a4b3eafed3438e35b4e4b28239
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>