forked from Mirrors/opensbi

We add a generic platform override callback to allow platform specific firmware init. Signed-off-by: Wei Liang Lim <weiliang.lim@starfivetech.com> Reviewed-by: Chee Hong Ang <cheehong.ang@starfivetech.com> Reviewed-by: Jun Liang Tan <junliang.tan@starfivetech.com> Reviewed-by: Anup Patel <anup@brainfault.org>