forked from Mirrors/opensbi

FDT gpio drivers have an extra .xlate operation, so they need to embed the `struct fdt_driver` inside the subsystem-specific type. The gpio subsystem always initializes the driver for a specific DT node. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org>