defconfig: firefly-rk3399: fix pinctrl config option

The option is named PINCTRL_ROCKCHIP_RK3399 not ROCKCHIP_RK3399_PINCTRL.
Set the correct option.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/firefly-rk3399_defconfig b/configs/firefly-rk3399_defconfig
index f30f131..0a4d005 100644
--- a/configs/firefly-rk3399_defconfig
+++ b/configs/firefly-rk3399_defconfig
@@ -39,7 +39,7 @@
 CONFIG_GMAC_ROCKCHIP=y
 CONFIG_PINCTRL=y
 CONFIG_SPL_PINCTRL=y
-CONFIG_ROCKCHIP_RK3399_PINCTRL=y
+CONFIG_PINCTRL_ROCKCHIP_RK3399=y
 CONFIG_DM_PMIC=y
 CONFIG_PMIC_RK8XX=y
 CONFIG_REGULATOR_PWM=y