rockchip: rk3328: Update default u-boot, spl-boot-order prop

Change to use a common FIT load order, same-as-spl > SD-card > eMMC on
RK3328 boards. Only EVB and Radxa ROCK Pi E is affected by this change.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>