Documentation/process: Add Google contact for embargoed hardware issues

This adds myself as the Google contact for embargoed hardware security
issues and fixes some small typos.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matt Linton <amuse@google.com>
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/201909040922.56496BF70@keescook
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>