forked from Mirrors/opensbi

Three macros are added. One is called BUG, which is used to put in an unreachable branch. One is called BUG_ON, which is used to check bugs and assert conditions are opposite. One is called SBI_ASSERT, used for assertion checking. Signed-off-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>