ARCVM: config: Enable RCU callback offloading on all CPUs

BUG=b:222463781
TEST=Cq, ARCVM CPU, GPU and Storage workloads

Signed-off-by: Parshuram Sangle <parshuram.sangle@intel.corp-partner.google.com>
Tested-by: Parshuram Sangle <parshuram.sangle@intel.corp-partner.google.com>
Change-Id: I6f7b463baf54a204be4e9a40ae87f7aa4a944eb5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/3890188


Reviewed-by: Joel Fernandes <joelaf@google.com>
Reviewed-by: Vineeth Pillai <vineethrp@google.com>
Signed-off-by: Richard Fung <richardfung@google.com>