mainboard/jetway/nf81-t56n-lf: Enable ACPI S3 support in Kconfig

Switch on ACPI suspend/resume support which now works after many cycles.

Change-Id: I94a9bc9f23c2b4482d940018d542ab89e6c76f09
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5406
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>