imx: Enable RTC (ds1307) support in the U-Boot proper on TPC70 board

The TPC70 is equipped with DS1307 RTC device. Add code to enable support
for it.
Signed-off-by: Lukasz Majewski <lukma@denx.de>

arch/arm/dts/imx6q-kp.dts

@@ -76,6 +76,11 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_i2c1>;
 	status = "okay";
+
+	ds1307: rtc@32 {
+		compatible = "dallas,ds1307";
+		reg = <0x32>;
+	};
 };
 
 &i2c2 {

configs/kp_imx6q_tpc_defconfig

@@ -62,6 +62,8 @@ CONFIG_SPL_PINCTRL=y
 CONFIG_PINCTRL_IMX6=y
 CONFIG_DM_REGULATOR_FIXED=y
 CONFIG_SPL_DM_REGULATOR_FIXED=y
+CONFIG_DM_RTC=y
+CONFIG_RTC_DS1307=y
 # CONFIG_REQUIRE_SERIAL_CONSOLE is not set
 CONFIG_MXC_UART=y
 CONFIG_SYSRESET=y