Enable BoringSSL optimizations on WoA

BoringSSL recently added Neon and hardware crypto optimization
support for the Windows on Arm (WoA) platform.

Enable use of these optimized functions in the Chromium BoringSSL
BUILD.gn file.

Change-Id: Ic5229f73f3a52bdb291f68819f4cb6862e1c4798
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2632753Reviewed-by: David Benjamin <davidben@chromium.org>
Commit-Queue: David Benjamin <davidben@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844184}

third_party/boringssl/BUILD.gn

@@ -100,6 +100,8 @@ if (is_win && !is_msan && current_cpu != "arm64") {
         # TODO(davidben): Rename all the file lists, etc., upstream from mac
         # and ios to apple.
         sources += crypto_sources_ios_aarch64
+      } else if (is_win) {
+        sources += crypto_sources_win_aarch64
       } else {
         public_configs = [ ":no_asm_config" ]
       }