fizz/nami: Use chipset_pre_init_callback

This change updates fizz/nami boards to use chipset_pre_init_callback
instead of hook.

BUG=b:78259506
BRANCH=None
TEST=make -j buildall

Change-Id: Ib09c033c2f0c2c3d324c90776f7bbd8365a71f52
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1018735
Commit-Ready: Furquan Shaikh <furquan@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>
4 files changed