rockchip: defconfig: puma-rk3399: enable RTC

commit: 52280315 ("rtc: rewrite isl1208 to support DM") enables us to
use the on-module RTC emulation with the rk3399 device model i2c driver.
Signed-off-by: NKlaus Goger <klaus.goger@theobroma-systems.com>
Acked-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>

configs/puma-rk3399_defconfig

@@ -80,6 +80,8 @@ CONFIG_REGULATOR_RK8XX=y
 CONFIG_PWM_ROCKCHIP=y
 CONFIG_RAM=y
 CONFIG_SPL_RAM=y
+CONFIG_DM_RTC=y
+CONFIG_RTC_ISL1208=y
 CONFIG_DEBUG_UART_BASE=0xFF180000
 CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_DEBUG_UART_SHIFT=2