Add a new CMOS variable which triggers activation of the

Add a new CMOS variable which triggers activation of the
LPT port. With the CMOS variable set, LPT is found by SeaBIOS,
with the variable reset, it's not.

Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Acked-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6302 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1