power: pmic: add the base MAX8907 PMIC support

Add basic i2c based read/write functions to access PMIC registers.

Tested-by: Ion Agorria <ion@agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/power/pmic/Makefile b/drivers/power/pmic/Makefile
index 2210b1a..6bebffb 100644
--- a/drivers/power/pmic/Makefile
+++ b/drivers/power/pmic/Makefile
@@ -7,6 +7,7 @@
 obj-$(CONFIG_$(PHASE_)DM_PMIC_FAN53555) += fan53555.o
 obj-$(CONFIG_$(PHASE_)DM_PMIC_DA9063) += da9063.o
 obj-$(CONFIG_$(PHASE_)DM_PMIC_MAX77663) += max77663.o
+obj-$(CONFIG_$(PHASE_)DM_PMIC_MAX8907) += max8907.o
 obj-$(CONFIG_DM_PMIC_MAX77686) += max77686.o
 obj-$(CONFIG_DM_PMIC_MAX8998) += max8998.o
 obj-$(CONFIG_DM_PMIC_MC34708) += mc34708.o