soc/amd/stoneyridge/: Get rid of device_t

Use of device_t has been abandoned in ramstage.

Change-Id: I84fbc90b2a81fe5476d659716f0d6e4f0d7e1de2
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/26458
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marc Jones <marc@marcjonesconsulting.com>
8 files changed