ARM: rmobile: Enable DM capable RCar I2C driver on Silk

Enable the DM capable driver instead of the legacy one.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

configs/silk_defconfig

@@ -54,6 +54,7 @@ CONFIG_CLK_RENESAS=y
 CONFIG_DM_GPIO=y
 CONFIG_RCAR_GPIO=y
 CONFIG_DM_I2C=y
+CONFIG_SYS_I2C_RCAR_I2C=y
 CONFIG_SYS_I2C_RCAR_IIC=y
 CONFIG_DM_MMC=y
 CONFIG_SH_MMCIF=y