reset: add reset controller driver for SCMI agents

This change introduces a reset controller driver for SCMI agent devices.
When SCMI agent and SCMI reset domain drivers are enabled, SCMI agent
binds a reset controller device for each SCMI reset domain protocol
devices enabled in the FDT.

SCMI reset driver is embedded upon CONFIG_RESET_SCMI=y. If enabled,
CONFIG_SCMI_AGENT is also enabled.

SCMI Reset Domain protocol is defined in the SCMI specification [1].

Links: [1] https://developer.arm.com/architectures/system-architectures/software-standards/scmi
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 3fdfe4a..b60e11f 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -181,4 +181,12 @@
 	  relevant. This driver provides a reset controller capable of
 	  interfacing with RPi4's co-processor and model these firmware
 	  initialization routines as reset lines.
+
+config RESET_SCMI
+	bool "Enable SCMI reset domain driver"
+	select SCMI_FIRMWARE
+	help
+	  Enable this option if you want to support reset controller
+	  devices exposed by a SCMI agent based on SCMI reset domain
+	  protocol communication with a SCMI server.
 endmenu