ARCVM: disable MEMCG for ARM builds

MEMCG used to be needed by lmkd, but it is no longer needed,
As PSI is the standard method to receive memory pressure events
on systems that support PSI (and ARCVM does).

BUG=b:254175034
TEST=Boot Arcvm, confirm memcg not enabled, run basic tast test;

Signed-off-by: Alex Gimenez <raging@google.com>
Change-Id: I0e2fa961e360bac6463c666bb19dce666308c460
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3969905


Reviewed-by: Suleiman Souhlal <suleiman@chromium.org>
Signed-off-by: Richard Fung <richardfung@google.com>