soc/rockchip: Get rid of device_t

Use of device_t has been abandoned in ramstage.

Change-Id: Idf47ea3b29c3fab7256d7a6722c7978594001d8d
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/26535
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
6 files changed