rk3288: config change for enable dram capacity auto-detect.

Enable ROCKCHIP_SPL_BACK_TO_BROM and disable CONFIG_SPL_MMC_SUPPORT
to save memory in order to enable add source code for dram capacity
auto-detect.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/configs/evb-rk3288_defconfig b/configs/evb-rk3288_defconfig
index fd8afe7..8db9041a 100644
--- a/configs/evb-rk3288_defconfig
+++ b/configs/evb-rk3288_defconfig
@@ -64,3 +64,4 @@
 CONFIG_USE_TINY_PRINTF=y
 CONFIG_CMD_DHRYSTONE=y
 CONFIG_ERRNO_STR=y
+CONFIG_ROCKCHIP_SPL_BACK_TO_BROM=y
diff --git a/configs/fennec-rk3288_defconfig b/configs/fennec-rk3288_defconfig
index 5b4d0f1..d5452004b 100644
--- a/configs/fennec-rk3288_defconfig
+++ b/configs/fennec-rk3288_defconfig
@@ -63,3 +63,4 @@
 CONFIG_USE_TINY_PRINTF=y
 CONFIG_CMD_DHRYSTONE=y
 CONFIG_ERRNO_STR=y
+CONFIG_ROCKCHIP_SPL_BACK_TO_BROM=y
diff --git a/configs/miniarm-rk3288_defconfig b/configs/miniarm-rk3288_defconfig
index 394e4aa..888563b 100644
--- a/configs/miniarm-rk3288_defconfig
+++ b/configs/miniarm-rk3288_defconfig
@@ -62,3 +62,4 @@
 CONFIG_USE_TINY_PRINTF=y
 CONFIG_CMD_DHRYSTONE=y
 CONFIG_ERRNO_STR=y
+CONFIG_ROCKCHIP_SPL_BACK_TO_BROM=y
diff --git a/configs/popmetal-rk3288_defconfig b/configs/popmetal-rk3288_defconfig
index ff6a153..1e70ae0 100644
--- a/configs/popmetal-rk3288_defconfig
+++ b/configs/popmetal-rk3288_defconfig
@@ -62,3 +62,4 @@
 CONFIG_USE_TINY_PRINTF=y
 CONFIG_CMD_DHRYSTONE=y
 CONFIG_ERRNO_STR=y
+CONFIG_ROCKCHIP_SPL_BACK_TO_BROM=y