power: make most tps drivers and the twl4030 driver compatible with DM_I2C

Those driver are not DM drivers per se (not using the PMIC/regulator
framework) and are using the legacy I2C API. Make them compatible with
the DM_I2C API.

This impacts the following drivers:
- palmas (used by am57xx/dra7xx evms)
- tps65218 (used by am43xx evms)
- tps65217 and tps65910 (used by am335x evms and am335x boneblack vboot)
- twl4030 (used by omap3_logicpd)
- tps65217 (used by brppt1)
- twl6030

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/include/palmas.h b/include/palmas.h
index 229de53..20c7e48 100644
--- a/include/palmas.h
+++ b/include/palmas.h
@@ -117,6 +117,7 @@
 #define BB_VSEL_VBAT		(3 << 1)
 #define BB_CHRG_EN		(1 << 0)
 
+#ifndef CONFIG_DM_I2C
 /*
  * Functions to read and write from TPS659038/TWL6035/TWL6037
  * or other Palmas family of TI PMICs
@@ -130,6 +131,10 @@
 {
 	return i2c_read(chip_no, reg, 1, val, 1);
 }
+#else
+int palmas_i2c_write_u8(u8 chip_no, u8 reg, u8 val);
+int palmas_i2c_read_u8(u8 chip_no, u8 reg, u8 *val);
+#endif
 
 void palmas_init_settings(void);
 int palmas_mmc1_poweron_ldo(uint ldo_volt, uint ldo_ctrl, uint voltage);