lenovo: Add lenovo_mainboard_partnumber.

Change-Id: Ie10dcb742fe0884dd94ff5960e2e4b116f633243
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/5246
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
acpigen: Add acpigen_write_irq.

Change-Id: Iba52dc2d52b7ac9a65d1d17b43e7204f5ede373e
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/5241
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>