fix(errata): workaround for Cortex-A510 erratum 1922240

Cortex-A510 erratum 1922240 is a Cat B erratum that applies to revision
r0p0 and is fixed in r0p1.

Since no errata framework code existed for A510 prior to this patch, it
has been added as well. Also some general cleanup changes in the CPU lib
makefile.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN2397239

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I8c427ef255cb4b38ed3e5c2c7444fcef957277e4
4 files changed