lib: utils/reset: Use fdt_driver for initialization

The reset driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_reset_init() performs a
best-effort initialization of all matching DT nodes. Platform-specific
logic expects exactly one DT node to match a single driver. This is
accomplished by using fdt_driver_init_one() with a local list containing
that one driver.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

lib/utils/reset/fdt_reset_atcwdt200.c

@@ -111,7 +111,7 @@ static const struct fdt_match atcwdt200_reset_match[] = {
 	{},
 };
 
-struct fdt_reset fdt_reset_atcwdt200 = {
+const struct fdt_driver fdt_reset_atcwdt200 = {
 	.match_table = atcwdt200_reset_match,
 	.init	     = atcwdt200_reset_init,
 };