windows_sdk: Fix docs to also mention arm64

Change-Id: I39fb0f99e62a822b9aa7d1b099c3a73e4499e051
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5345456
Auto-Submit: David Benjamin <davidben@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>

recipes/README.recipes.md

@@ -1016,7 +1016,7 @@ Args:
   * version (str): CIPD version of the SDK
     (default is set via $infra/windows_sdk.version property)
   * enabled (bool): Whether the SDK should be used or not.
-  * target_arch (str): 'x86' or 'x64'.
+  * target_arch (str): 'x86', 'x64', or 'arm64'
 
 Yields:
   If enabled, yields SDKPaths object with paths to well-known roots within

recipes/recipe_modules/windows_sdk/api.py

@@ -39,7 +39,7 @@ class WindowsSDKApi(recipe_api.RecipeApi):
       * version (str): CIPD version of the SDK
         (default is set via $infra/windows_sdk.version property)
       * enabled (bool): Whether the SDK should be used or not.
-      * target_arch (str): 'x86' or 'x64'.
+      * target_arch (str): 'x86', 'x64', or 'arm64'
 
     Yields:
       If enabled, yields SDKPaths object with paths to well-known roots within
@@ -94,7 +94,7 @@ class WindowsSDKApi(recipe_api.RecipeApi):
 
     Args:
       * sdk_dir (path): Path to a directory containing the SDK.
-      * target_arch (str): 'x86' or 'x64'
+      * target_arch (str): 'x86', 'x64', or 'arm64'
     """
     env = {}
     env_prefixes = {}