video: move tegra dc driver into own folder

Move tegra dc driver to tegra20 directory and also mention
T30 in description of the driver's config option.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
[agust: add commit description]
Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/drivers/video/tegra20/Kconfig b/drivers/video/tegra20/Kconfig
new file mode 100644
index 0000000..2a4036b
--- /dev/null
+++ b/drivers/video/tegra20/Kconfig
@@ -0,0 +1,8 @@
+config VIDEO_TEGRA20
+	bool "Enable Display Controller support on Tegra20 and Tegra 30"
+	depends on OF_CONTROL
+	help
+	   T20/T30 support 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.