power: pmic: Add a driver for X-Powers AXP PMICs

These PMICs provide some combination of battery charger, fuel gauge,
GPIOs, regulators, and VBUS routing. These functions are represented
as child nodes in the device tree. Add the minimal driver needed to
probe these child devices and provide the DM_PMIC ops.

Enable the driver by default for SoCs that normally pair with a PMIC.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
index e8a0432..fcb517f 100644
--- a/drivers/power/pmic/Kconfig
+++ b/drivers/power/pmic/Kconfig
@@ -63,6 +63,20 @@
 	functions. It uses an I2C interface and is designed for use with
 	tablets and smartphones.
 
+config PMIC_AXP
+	bool "Enable Driver Model for X-Powers AXP PMICs"
+	depends on DM_I2C
+	help
+	  This config enables driver-model PMIC uclass features for
+	  X-Powers AXP152, AXP2xx, and AXP8xx PMICs.
+
+config SPL_PMIC_AXP
+	bool "Enable Driver Model for X-Powers AXP PMICs in SPL"
+	depends on SPL_DM_I2C && SPL_DM_PMIC
+	help
+	  This config enables driver-model PMIC uclass features in the SPL for
+	  X-Powers AXP152, AXP2xx, and AXP8xx PMICs.
+
 config DM_PMIC_DA9063
 	bool "Enable Driver Model for the Dialog DA9063 PMIC"
 	help