tegra20: rename tegra2 -> tegra20

This is make naming consistent with the kernel and devicetree and in
preparation of pulling out the common tegra20 code.

Signed-off-by: Allen Martin <amartin@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/include/serial.h b/include/serial.h
index 5173499..cbdf8a9 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -31,7 +31,7 @@
 	defined(CONFIG_MB86R0x) || defined(CONFIG_MPC5xxx) || \
 	defined(CONFIG_MPC83xx) || defined(CONFIG_MPC85xx) || \
 	defined(CONFIG_MPC86xx) || defined(CONFIG_SYS_SC520) || \
-	defined(CONFIG_TEGRA2) || defined(CONFIG_SYS_COREBOOT)
+	defined(CONFIG_TEGRA20) || defined(CONFIG_SYS_COREBOOT)
 extern struct serial_device serial0_device;
 extern struct serial_device serial1_device;
 #if defined(CONFIG_SYS_NS16550_SERIAL)