forked from Mirrors/opensbi

This patch adds documentation for qemu/virt and qemu/sifive_u platform supports. Signed-off-by: Anup Patel <anup.patel@wdc.com>
This patch adds documentation for qemu/virt and qemu/sifive_u platform supports. Signed-off-by: Anup Patel <anup.patel@wdc.com>