rockchip: defconfig: firefly-rk3399: sync up with SPL changes for ATF

This tracks the SPL changes for ATF for the Firefly:
 * renames ATF_SUPPORT to ATF
 * drops CONFIG_SPL_ATF_TEXT_BASE

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

configs/firefly-rk3399_defconfig

@@ -12,8 +12,7 @@ CONFIG_SPL_LOAD_FIT=y
 # CONFIG_DISPLAY_CPUINFO is not set
 CONFIG_SPL_STACK_R=y
 CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x4000
-CONFIG_SPL_ATF_SUPPORT=y
-CONFIG_SPL_ATF_TEXT_BASE=0x00010000
+CONFIG_SPL_ATF=y
 CONFIG_CMD_BOOTZ=y
 CONFIG_CMD_GPT=y
 CONFIG_CMD_MMC=y