fsp_broadwell_de: Switch CPU to high frequency mode

According to Yang York the FSP is responsible for switching the CPU into
high frequency mode (HFM). For an unknown reason this is not done for the
BSP on my platform though the APs are switched properly.
This code switches the CPU into HFM which makes sure that all cores are in
high frequency mode before payload is started.

It should not harm the operation even if FSP was successful in switching
to HFM.

Change-Id: I91baf538511747d1692a8b6b359df5c3a8d56848
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/19537
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed