tegra: video: Rename CONFIG_VIDEO_TEGRA to CONFIG_VIDEO_TEGRA20

This option refers only to the tegra20 video driver, so name it as such
to avoid confusion with tegra124.

Also move this option to Kconfig.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 72afae0..b6c0e3c 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -381,6 +381,14 @@
 	  console device and can display stdout output. Within U-Boot is is
 	  a normal bitmap display and can display images as well as text.
 
+config VIDEO_TEGRA20
+	bool "Enable LCD support on Tegra20"
+	help
+	   Tegra20 supports video output to an attached LCD panel as well as
+	   other options such as HDMI. Only the LCD is supported in U-Boot.
+	   This option enables this support which can be used on devices which
+	   have an LCD display connected.
+
 config VIDEO_TEGRA124
 	bool "Enable video support on Tegra124"
 	depends on DM_VIDEO