This commit improves ARM platform matching in two instances:

* Some old kernels reported the CPU architecture of arm64 cpus as
  Aarch64 [1].
* In cases where the user is running with armv8 cpu and kernel but amrhf
  user land (so armhf containerd), a possibility given the compatibility
  of armv8 with armv7.

[1] https://elixir.bootlin.com/linux/v3.14.29/source/arch/arm64/kernel/setup.c#L420

Signed-off-by: Jaime Caamaño Ruiz <jcaamano@suse.com>