mx23evk: Convert to CONFIG_DM_SERIAL

The conversion to CONFIG_DM_SERIAL is mandatory, so select this option.

Signed-off-by: Fabio Estevam <festevam@denx.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e00c9ee..ac079da 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -912,7 +912,7 @@
 	select CPU_ARM926EJS
 	select GPIO_EXTRA_HEADER
 	select MACH_IMX
-	select PL011_SERIAL
+	select PL011_SERIAL if !TARGET_MX23EVK
 	select SUPPORT_SPL
 
 config ARCH_MX28
diff --git a/arch/arm/mach-imx/mxs/Kconfig b/arch/arm/mach-imx/mxs/Kconfig
index 0fd4758..6b9d5c9 100644
--- a/arch/arm/mach-imx/mxs/Kconfig
+++ b/arch/arm/mach-imx/mxs/Kconfig
@@ -14,6 +14,7 @@
 
 config TARGET_MX23EVK
 	bool "Support mx23evk"
+	select PL01X_SERIAL
 	select BOARD_EARLY_INIT_F
 
 config TARGET_XFI3
diff --git a/configs/mx23evk_defconfig b/configs/mx23evk_defconfig
index 3602ead..7d0e7cc 100644
--- a/configs/mx23evk_defconfig
+++ b/configs/mx23evk_defconfig
@@ -49,6 +49,7 @@
 CONFIG_DM_REGULATOR_FIXED=y
 CONFIG_DM_REGULATOR_GPIO=y
 CONFIG_CONS_INDEX=0
+CONFIG_DM_SERIAL=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_STORAGE=y