arm64: cpuinfo: ARMv7 compatable cpuinfo option

To be backwards compatable with the output of cpuinfo on an ARMv7,
print the features that were optional in ARMv7 but are required in
ARMv8.

Change-Id: Ic728f71be4a971adc79ef552f25cfbf95a4dac29
Signed-off-by: Alex Van Brunt <avanbrunt@nvidia.com>
Reviewed-on: http://git-master/r/366095


Reviewed-by: Richard Wiley <rwiley@nvidia.com>
Tested-by: Oskari Jaaskelainen <oskarij@nvidia.com>