serial: omap: Introduce DM specific omap serial

Add driver model support for OMAP_SERIAL while reusing
the functions in ns16550.c

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Tested-by: Derald D. Woods <woods.technical@gmail.com>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 766e5ce..41f43af 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -625,6 +625,15 @@
 	  for example APQ8016 and MSM8916.
 	  Single baudrate is supported in current implementation (115200).
 
+config OMAP_SERIAL
+	bool "Support for OMAP specific UART"
+	depends on DM_SERIAL
+	default y if ARCH_OMAP2PLUS
+	select SYS_NS16550
+	help
+	  If you have an TI based SoC and want to use the on-chip serial
+	  port, say Y to this option. If unsure say N.
+
 config OWL_SERIAL
 	bool "Actions Semi OWL UART"
 	depends on DM_SERIAL && ARCH_OWL