[roll third_party/pigweed] pw_tls_client_boringssl: Add scaffolding

Original-Bug: 421
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/51681

third_party/pigweed Rolled-Commits: 01fc15be6a16ae3..ba9e06db0259b37
Roller-URL: https://ci.chromium.org/b/8842804781940061904
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8842804781940061904
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I674f05cb3b4709e712eb472e62da07b0e8b53212
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/52141
Reviewed-by: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 01fc15b..ba9e06d 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 01fc15be6a16ae37fff770129d3a2652f3d0719e
+Subproject commit ba9e06db0259b37b104182b0ceced9825709ab21