roll: pigweed, pw_toolchain: pw_stream_uart_linux: Add Config struct

The config struct only has two basic properties for configuring the
UART - the baudrate, and a new property added by this change for
enabling flow control.

We opt to make the properties to the Config struct as std::optional to
allow the user to "keep" the default behaviour / previously set tty
behaviour. This maintains backwards compatability of this API and also
more closely resembles the Linux tty interface.

Original-Bug: 331871421
Test: CRTSCTS bit is processed on device serial uart driver on Open
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/233591

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: 2fbf9d847123b2e..114064192788e79
Roller-URL: https://ci.chromium.org/b/8737702145734827761
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I45b79ef63bc03c246cb145fbed70ae9fe9924b34
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/showcase/sense/+/234011
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/MODULE.bazel b/MODULE.bazel
index 474a7fb..813184c 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -50,8 +50,8 @@
     module_name = "pigweed",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-09-04.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8737703945684849953.
-    commit = "2fbf9d847123b2ed2dfa2e9ff61cec2ba30324fc",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8737702145734827761.
+    commit = "114064192788e798a874673639f712441b803af4",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed",
 )
 
@@ -59,8 +59,8 @@
     module_name = "pw_toolchain",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-09-04.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8737703945684849953.
-    commit = "2fbf9d847123b2ed2dfa2e9ff61cec2ba30324fc",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8737702145734827761.
+    commit = "114064192788e798a874673639f712441b803af4",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed",
     strip_prefix = "pw_toolchain_bazel",
 )