imx: move serial driver to drivers/serial

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 6ab847f..705ae47 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -34,6 +34,7 @@
 COBJS-$(CONFIG_S3C64XX) += s3c64xx.o
 COBJS-$(CONFIG_SYS_NS16550_SERIAL) += serial.o
 COBJS-$(CONFIG_CLPS7111_SERIAL) += serial_clps7111.o
+COBJS-$(CONFIG_IMX_SERIAL) += serial_imx.o
 COBJS-$(CONFIG_IXP_SERIAL) += serial_ixp.o
 COBJS-$(CONFIG_KS8695_SERIAL) += serial_ks8695.o
 COBJS-$(CONFIG_LPC2292_SERIAL) += serial_lpc2292.o