Documentation: embargoed-hardware-issues.rst: clean out empty and unused entries

There are a few empty entries in the company/project list, which
confuses people as to why they are there, so remove them entirely, and
also remove an entry that doesn't wish to participate in this process.

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/2023062742-mouse-appease-7917@gregkh


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>