CHROMIUM: config: Don't set CONFIG_TRACEFS_DISABLE_AUTOMOUNT for arm64

ARCVM mounts debugfs in tast dev mode environment for ureadahead tracing
to function during the ChromeOS Android Uprev build process. In order
for arc.DataCollector tast to run ureadahead in tracing mode on arm64
devices, /sys/kernel/debug/tracing/* needs to be mounted. x86_64 config
also does not have this config set where ureadahead tracing is working.

Note that debugfs is not mounted in production where ureadahead operates
in default / readahead mode as required by GTS (and therefore tracefs is
not automounted in production).

BUG=b:265969396
BUG=b:259450728
BUG=b:180359699
TEST=Use modprobe configs and zcat /proc/config.gz on kukui to confirm
configuration items are not set.
TEST=Manually verified /sys/kernel/debug/tracing/* is mounted with RO
boot flag ro.boot.arcvm_mount_debugfs=1.
TEST=tast run $DUT arc.DataCollector.vm_r_local

Signed-off-by: Alan Ding <alanding@google.com>
Change-Id: I49540a1f7cf886b9af102bf5b89b8956330ecbc6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4183045


Reviewed-by: Hikaru Nishida <hikalium@chromium.org>
Tested-by: Alan Ding <alanding@chromium.org>
Reviewed-by: Lepton Wu <lepton@chromium.org>
Commit-Queue: Alan Ding <alanding@chromium.org>
Reviewed-by: Masami Hiramatsu <mhiramat@google.com>
Signed-off-by: Richard Fung <richardfung@google.com>