rockchip: configs: correct env offset when enable CONFIG_ROCKCHIP_SPL_BACK_TO_BROM

With CONFIG_ROCKCHIP_SPL_BACK_TO_BROM enabled,
the environment is inside u-boot.
So solve it by moving environment after u-boot.

Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
diff --git a/include/configs/fennec_rk3288.h b/include/configs/fennec_rk3288.h
index 77b647e..554ca0e 100644
--- a/include/configs/fennec_rk3288.h
+++ b/include/configs/fennec_rk3288.h
@@ -12,11 +12,20 @@
 
 #define CONFIG_ENV_IS_IN_MMC
 #define CONFIG_SYS_MMC_ENV_DEV 1
+
+#ifdef CONFIG_ROCKCHIP_SPL_BACK_TO_BROM
+/* SPL @ 32k for 34k
+ * u-boot directly after @ 68k for 400k or so
+ * ENV @ 992k
+ */
+#define CONFIG_ENV_OFFSET ((1024-32) * 1024)
+#else
 /* SPL @ 32k for ~36k
  * ENV @ 96k
  * u-boot @ 128K
  */
 #define CONFIG_ENV_OFFSET (96 * 1024)
+#endif
 
 #define CONFIG_SYS_WHITE_ON_BLACK