msm: cache_erp: Use dedicated location for ERP event logging

Use a dedicated memory address for the ERP event log rather
than reusing a deprecated address from an earlier event
logging mechanism.

Change-Id: I647ca194718f101faa3ed4fd829a9b20da6489e9
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>