refactor(cpus): move errata check to common code

This patch centralizes some of the Errata ABI code
that could be used for checking if an Errata has been applied
to cpu library since the function is mostly generic.

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I2c6d4468f7125d4d99ccdebc5ea8f9e4390360cc
3 files changed