drivers: edac: Update the register offsets

Update the register offsets as per the SW interface document. And use
the pvt_info member of edev structure to store the platform device
private data so that the cache error poll function can access the
private data without container_of macro. Update the Kconfig dependency
to make llcc edac driver on llcc core driver.

Change-Id: I66a8dbcfb7bcec98e81a2cb33026d9396f89da63
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>