Explicitly add -mfpu=neon to all targets that use NEON

Remove obsolete comment about Chromium not defining NEON for Android.

Semi-related fix: don't use `rtc_remove_configs` directly, `suppressed_configs` is the "public interface".

Bug: webrtc:9579
Change-Id: I512628feb462a29432f1356cfef00efe1ddaf84f
Reviewed-on: https://webrtc-review.googlesource.com/91761
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Per Ã…hgren <peah@webrtc.org>
Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24165}
diff --git a/BUILD.gn b/BUILD.gn
index 072d408..3f07fdb 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -330,7 +330,7 @@
 
     sources = []
     complete_static_lib = true
-    rtc_remove_configs = [ "//build/config/compiler:thin_archive" ]
+    suppressed_configs += [ "//build/config/compiler:thin_archive" ]
     defines = []
 
     deps = [