regulator: bd71837: copy the bd71837 pmic driver from NXP imx u-boot

https://source.codeaurora.org/external/imx/uboot-imx

cherry picked, styled and merged commits:
- MLK-18387 pmic: Add pmic driver for BD71837: e9a3bec2e95a
- MLK-18590 pmic: bd71837: Change to use new fdt API: acdc5c297a96

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/power/pmic/Makefile b/drivers/power/pmic/Makefile
index ce250cb..888dbb2 100644
--- a/drivers/power/pmic/Makefile
+++ b/drivers/power/pmic/Makefile
@@ -8,6 +8,7 @@
 obj-$(CONFIG_DM_PMIC_MAX77686) += max77686.o
 obj-$(CONFIG_DM_PMIC_MAX8998) += max8998.o
 obj-$(CONFIG_DM_PMIC_MC34708) += mc34708.o
+obj-$(CONFIG_$(SPL_)DM_PMIC_BD71837) += bd71837.o
 obj-$(CONFIG_$(SPL_)DM_PMIC_PFUZE100) += pfuze100.o
 obj-$(CONFIG_PMIC_S2MPS11) += s2mps11.o
 obj-$(CONFIG_DM_PMIC_SANDBOX) += sandbox.o i2c_pmic_emul.o