src/*: normalize Google copyright headers

As per internal discussion, there's no "ChromiumOS Authors" that's
meaningful outside the Chromium OS project, so change everything to the
contemporary "Google LLC."

While at it, also ensure consistency in the LLC variants (exactly one
trailing period).

"Google Inc" does not need to be touched, so leave them alone.

Change-Id: Ia0780e31cdab879d2aaef62a2f0403e3db0a4ac8
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/28756
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Joel Kitching <kitching@google.com>

src/cpu/amd/car/post_cache_as_ram.c

@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2015 Timothy Pearson <tpearson@raptorengineeringinc.com>,
  *	 Raptor Engineering
- * Copyright (C) 2012 ChromeOS Authors
+ * Copyright (C) 2012 Google LLC
  * 2005.6 by yhlu
  * 2006.3 yhlu add copy data from CAR to ram
  *