[roll third_party/pigweed] pw_build: Clarify docs on pw_elf_to_bin

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/213616
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https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 1d82b0ff4c571fe..3d3e59c25557e05
Roller-URL: https://ci.chromium.org/b/8745832803851184913
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I472bbd80f6c45966aa7bf2b90addabbe8a4e21ea
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/214558
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
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diff --git a/third_party/pigweed b/third_party/pigweed
index 1d82b0f..3d3e59c 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1d82b0ff4c571fe6d1c7fff55a0ae563ffe42103
+Subproject commit 3d3e59c25557e050da028273db776ba854182fe0