roll: third_party/pigweed pw_interrupt_freertos: Add pw_interrupt backend for FreeRTOS

This replaces the pw_interrupt_cortex_a module which does not work
correctly.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/267292
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Original-Revision: 7ab1856e8c062ae18a6947479ef0dc60244e345d

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 0481c3fccfd309..7ab1856e8c062a
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8722976251380241505
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I05329b4385c3abf0934310e06ceb013aed39aec8
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/267837
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
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 0481c3f..7ab1856 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 0481c3fccfd3090459cca4428078fa540b443b1c
+Subproject commit 7ab1856e8c062ae18a6947479ef0dc60244e345d