pmic: add stpmu1 support

This driver implements register read/write operations for STPMU1.

The STPMU1 PMIC provides 4 BUCKs, 6 LDOs, 1 VREF
and 2 power switches. It is accessed via an I2C interface.
This device is used with STM32MP1 SoCs.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
index 5d49c93..40ab9f7 100644
--- a/drivers/power/pmic/Kconfig
+++ b/drivers/power/pmic/Kconfig
@@ -209,3 +209,11 @@
 	The TPS65910 is a PMIC containing 3 buck DC-DC converters, one boost
 	DC-DC converter, 8 LDOs and a RTC. This driver binds the SMPS and LDO
 	pmic children.
+
+config PMIC_STPMU1
+	bool "Enable support for STMicroelectronics STPMU1 PMIC"
+	depends on DM_PMIC && DM_I2C
+	---help---
+	The STPMU1 PMIC provides 4 BUCKs, 6 LDOs, 1 VREF and 2 power switches.
+	It is accessed via an I2C interface. The device is used with STM32MP1
+	SoCs. This driver implements register read/write operations.