[third_party/pigweed] Roll 2 commits

0540acc0b8bf0b1 pw_spi_linux: Move linux_spi from pw_spi to its ow
8a7744c250833e0 third_party/freertos: Fix typo in docs

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 0dafca3ccc0927b..0540acc0b8bf0b1
Roller-URL: https://ci.chromium.org/b/8751733294138179409
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I7c6e02f6c45b87b8e5bc3b223e1537fb1599f335
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/201612
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 0dafca3..0540acc 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 0dafca3ccc0927bce5be50a8cad46c03d58f6a65
+Subproject commit 0540acc0b8bf0b1224e159c51ee69290218d661e