mx23_olinuxino: 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 ac079da..b3115b0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -912,7 +912,6 @@
 	select CPU_ARM926EJS
 	select GPIO_EXTRA_HEADER
 	select MACH_IMX
-	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 6b9d5c9..d3233d8 100644
--- a/arch/arm/mach-imx/mxs/Kconfig
+++ b/arch/arm/mach-imx/mxs/Kconfig
@@ -10,6 +10,7 @@
 
 config TARGET_MX23_OLINUXINO
 	bool "Support mx23_olinuxino"
+	select PL01X_SERIAL
 	select BOARD_EARLY_INIT_F
 
 config TARGET_MX23EVK
diff --git a/configs/mx23_olinuxino_defconfig b/configs/mx23_olinuxino_defconfig
index 89b69fb..24968e1 100644
--- a/configs/mx23_olinuxino_defconfig
+++ b/configs/mx23_olinuxino_defconfig
@@ -50,6 +50,7 @@
 CONFIG_LED_STATUS_CMD=y
 CONFIG_MMC_MXS=y
 CONFIG_CONS_INDEX=0
+CONFIG_DM_SERIAL=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_HOST_ETHER=y