tflite: npu: Add Pad op support

Implement padding operation to enable facedetector_front.tflite

BUG=b:343331090
TEST=stable_delegate_test_suite --stable_delegate_settings_file=settings.json --gtest_filter=PadOpTest*
TEST=benchmark_model --graph=facedetector_front_random.tflite --stable_delegate_settings_file=settings.json

Cq-Depend: chromium:5599315
Change-Id: Ib5d20a26104f0b2a52da4d138dd7c330d38b5cca
Signed-Off-by: Vijeetkumar Benni <vijeetkumar.benni@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/tflite/+/5607972
Reviewed-by: Shik Chen <shik@chromium.org>
Commit-Queue: ChromeOS Auto Retry <chromeos-auto-retry@chromeos-bot.iam.gserviceaccount.com>
8 files changed