pmic: Add Renesas RAA215300 PMIC driver

The RZ/G2L SMARC module is powered via a Renesas RAA215300 PMIC which
provides several voltage converters, a real time clock (RTC) and reset
control. A basic driver is implemented for this device so that we can
read, write and dump the PMIC registers.

The raa215300_bind() function is added as a stub, binding of the
sysreset driver will be added in a later patch.

Additional features of this PMIC (such as reset control) may be
supported by future patches.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
index 454a6e0..9b61b18 100644
--- a/drivers/power/pmic/Kconfig
+++ b/drivers/power/pmic/Kconfig
@@ -404,6 +404,15 @@
 	help
 	The TPS65219 is a PMIC containing a bunch of SMPS & LDOs.
 	This driver binds the pmic children.
+
+config PMIC_RAA215300
+	bool "Renesas RAA215300 PMIC driver"
+	depends on DM_PMIC
+	help
+	  The Renesas RAA215300 PMIC driver includes RTC support, system reset
+	  support and several voltage regulators. For now, this driver simply
+	  allows register access and will bind the sysreset driver
+	  (CONFIG_SYSRESET_RAA215300) if it is enabled.
 endif
 
 config PMIC_TPS65217