Extend both the CMake and BUILD.gn configurations to support building a
library with the Arm Scalable Matrix Extension (SME). Add an initial
(empty) rotate_sme.cc source file to populate the library for now.
Change-Id: Icd4bd6a8ce72ba132299b00c99478a18a85d869a
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5588664
Reviewed-by: Justin Green <greenjustin@google.com>
Reviewed-by: Frank Barchard <fbarchard@chromium.org>
