fsp_broadwell_de: Add ability to set PCIe completion timeout

This enables the user to set the completion timeout value in PCI
Express Device Control 2 register via devicetree.cb.

Based on corebootBDE-270-iou-complto.patch in Arista EOS 4.20 release.

Change-Id: If0527899bc2047d0e57c11f7801768d07f9a5179
Signed-off-by: David Hendricks <dhendricks@fb.com>
Reviewed-on: https://review.coreboot.org/26225
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
3 files changed