configs: trats2: enable the max77686 regulator config

Enable the CONFIG_DM_REGULATOR_MAX77686 for using regulator driver.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>

configs/trats2_defconfig

@@ -37,6 +37,8 @@ CONFIG_MMC_SDHCI_SDMA=y
 CONFIG_MMC_SDHCI_S5P=y
 CONFIG_DM_PMIC=y
 CONFIG_DM_PMIC_MAX77686=y
+CONFIG_DM_REGULATOR=y
+CONFIG_DM_REGULATOR_MAX77686=y
 CONFIG_USB=y
 CONFIG_DM_USB=y
 CONFIG_USB_GADGET=y