lib: utils: Mark RPMI drivers as experimental

These drivers were merged on an experimental basis without the RPMI
specification being frozen. As a result, they may not be compatible with
the frozen version of the RPMI protocol. Additionally, their devicetree
bindings have not been reviewed and are subject to change. Warn the user
that these drivers make no compatibility guarantees, and that their
behavior and devicetree bindings may change incompatibly in future
versions of OpenSBI.

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

lib/utils/hsm/fdt_hsm_rpmi.c

@@ -359,4 +359,5 @@ static const struct fdt_match rpmi_hsm_match[] = {
 struct fdt_driver fdt_hsm_rpmi = {
 	.match_table = rpmi_hsm_match,
 	.init = rpmi_hsm_cold_init,
+	.experimental = true,
 };