dm: tegra: Enable driver model for serial

Use driver model for serial ports.

Since Tegra now uses driver model for serial, adjust the definition of
V_NS16550_CLK so that it is clear that this is only used for SPL.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/tegra-common.h b/include/configs/tegra-common.h
index f1187f1..834b3d5 100644
--- a/include/configs/tegra-common.h
+++ b/include/configs/tegra-common.h
@@ -21,6 +21,9 @@
 #define CONFIG_DM
 #define CONFIG_CMD_DM
 #define CONFIG_DM_GPIO
+#ifndef CONFIG_SPL_BUILD
+#define CONFIG_DM_SERIAL
+#endif
 
 #define CONFIG_SYS_TIMER_RATE		1000000
 #define CONFIG_SYS_TIMER_COUNTER	NV_PA_TMRUS_BASE
@@ -46,10 +49,14 @@
 /*
  * NS16550 Configuration
  */
-#define CONFIG_SYS_NS16550
+#ifdef CONFIG_SPL_BUILD
 #define CONFIG_SYS_NS16550_SERIAL
 #define CONFIG_SYS_NS16550_REG_SIZE	(-4)
 #define CONFIG_SYS_NS16550_CLK		V_NS16550_CLK
+#else
+#define CONFIG_TEGRA_SERIAL
+#endif
+#define CONFIG_SYS_NS16550
 
 /*
  * Common HW configuration.