Set PCIe "Enable Clock Power Management", if endpoint supports it. BUG=chrome-os-partner:31424 BRANCH=none TEST=build and boot on rambi, check Enable Clock Power Management in link control register is set properly Change-Id: Ie54110d1ef42184cfcf47c9fe4d735960aebe47f Signed-off-by: Kane Chen <kane.chen@intel.com> Reviewed-on: https://chromium-review.googlesource.com/220742 Reviewed-by: Duncan Laurie <dlaurie@chromium.org> [Edit commit message.] Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-on: http://review.coreboot.org/8447 Tested-by: build bot (Jenkins) Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>