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

All the Zynq boards have switch to Driver Model.
"select DM" is better than default value in each defconfig.

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

arch/arm/Kconfig

@@ -650,6 +650,7 @@ config ZYNQ
 	bool "Xilinx Zynq Platform"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
 
 config TARGET_XILINX_ZYNQMP
 	bool "Support Xilinx ZynqMP Platform"

configs/zynq_microzed_defconfig

@@ -7,5 +7,4 @@ CONFIG_OF_CONTROL=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y
 CONFIG_DEFAULT_DEVICE_TREE="zynq-microzed"

configs/zynq_zc70x_defconfig

@@ -8,4 +8,3 @@ CONFIG_DEFAULT_DEVICE_TREE="zynq-zc702"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y

configs/zynq_zc770_xm010_defconfig

@@ -9,4 +9,3 @@ CONFIG_DEFAULT_DEVICE_TREE="zynq-zc770-xm010"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y

configs/zynq_zc770_xm012_defconfig

@@ -9,4 +9,3 @@ CONFIG_DEFAULT_DEVICE_TREE="zynq-zc770-xm012"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y

configs/zynq_zc770_xm013_defconfig

@@ -9,4 +9,3 @@ CONFIG_DEFAULT_DEVICE_TREE="zynq-zc770-xm013"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y

configs/zynq_zed_defconfig

@@ -8,4 +8,3 @@ CONFIG_DEFAULT_DEVICE_TREE="zynq-zed"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y

configs/zynq_zybo_defconfig

@@ -8,4 +8,3 @@ CONFIG_DEFAULT_DEVICE_TREE="zynq-zybo"
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_SIGNATURE=y
-CONFIG_DM=y