driver: edac: octeontx: Improvements to GIC RAS handler

commit 68ddf2749c2baa4589a5b95e2a3f93688a202627 from
git@git.assembla.com:cavium/WindRiver.linux.git

Has the following changes:
  - do not print explicit error message when ghes node for
    gic is not present
  - Use generic version to remove gic ras handler

Signed-off-by: Chandrakala Chavva <cchavva@cavium.com>
Change-Id: Id17eabd500716ba2e58c8bf1f2fcc3e5a18fccb8
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/115313


Reviewed-by: Chandrakala Chavva <cchavva@marvell.com>
Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>