ARM: snapper9260: 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/mach-at91/Kconfig

@@ -30,6 +30,9 @@ config TARGET_TNY_A9260
 config TARGET_SNAPPER9260
 	bool "Support snapper9260"
 	select CPU_ARM926EJS
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_AFEB9260
 	bool "Support afeb9260"

configs/snapper9260_defconfig

@@ -2,6 +2,3 @@ CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9260"
 CONFIG_ARM=y
 CONFIG_ARCH_AT91=y
 CONFIG_TARGET_SNAPPER9260=y
-CONFIG_DM=y
-CONFIG_DM_GPIO=y
-CONFIG_DM_SERIAL=y

configs/snapper9g20_defconfig

@@ -2,6 +2,3 @@ CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9G20"
 CONFIG_ARM=y
 CONFIG_ARCH_AT91=y
 CONFIG_TARGET_SNAPPER9260=y
-CONFIG_DM=y
-CONFIG_DM_GPIO=y
-CONFIG_DM_SERIAL=y