Revert "rainier and tacoma: Build u-boot spl"

This reverts commit f2f334e6221b659934a8e72f5ca1aa8c9b8ae173.

The u-boot openbmc spl defconfig is still in review:
https://patchwork.ozlabs.org/project/openbmc/patch/1586370073-71433-1-git-send-email-anoo@linux.ibm.com/

Change-Id: I58b1da70d8b970ced51ef0d84673ffa42e5422c4
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
2 files changed