ANDROID: scs: use vmapped shadow stacks by default

Enable CONFIG_SHADOW_CALL_STACK_VMAP by default, and as we allocate
a full page for the stack, allow the kernel use all of it.

Bug: 169781940
Change-Id: Ie8eaa7f24e9bf10ff28a302ac98ad843b71c9c2a
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Git-commit: 1eb12882
Git-repo: https://android.googlesource.com/kernel/common/+/refs/heads/android11-5.4


Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>