ACPI: Remove /proc/acpi/embedded_controller/..

Other patches in this series add the same info to /sys/... and
/proc/ioports.

The info removed should never have been used in an application,
eventually someone read it manually.
/proc/acpi is deprecated for more than a year anyway...

Signed-off-by: Thomas Renninger <trenn@suse.de>

CC: Alexey Starikovskiy <astarikovskiy@suse.de>
CC: Len Brown <lenb@kernel.org>
CC: linux-kernel@vger.kernel.org
CC: linux-acpi@vger.kernel.org
CC: platform-driver-x86@vger.kernel.org
Signed-off-by: Matthew Garrett <mjg@redhat.com>