ARM: cm_fx6: use "select" instead of default value in defconfig

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>

arch/arm/Kconfig

@@ -630,6 +630,9 @@ config TARGET_CM_FX6
 	bool "Support cm_fx6"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_SOCFPGA_ARRIA5
 	bool "Support socfpga_arria5"

configs/cm_fx6_defconfig

@@ -2,6 +2,3 @@ CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,MX6QDL,SPL"
 CONFIG_ARM=y
 CONFIG_TARGET_CM_FX6=y
-CONFIG_DM=y
-CONFIG_DM_GPIO=y
-CONFIG_DM_SERIAL=y