tegra2: Add Avionic Design Plutux support.

The Plutux is a set-top box device based on the Tamonten processor
module. It can be connected to a display via an HDMI output.

Changes in v3:
  * Remove unused implementation of gpio_config_uart().
  * Implement MMC/SD card detection.
  * Drop board_mmc_getcd() which is now implemented by common Tegra2
    code.
  * Add MAINTAINERS entry.

Changes in v2:
  * No longer override the default CONFIG_SYS_TEXT_BASE setting.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/boards.cfg b/boards.cfg
index 406d64d..e70cc86 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -245,6 +245,7 @@
 zipitz2                      arm         pxa
 colibri_pxa270               arm         pxa         -                   toradex
 jornada                      arm         sa1100
+plutux                       arm         armv7       plutux              avionic-design tegra2
 atngw100                     avr32       at32ap      -                   atmel          at32ap700x
 atstk1002                    avr32       at32ap      atstk1000           atmel          at32ap700x
 atstk1003                    avr32       at32ap      atstk1000           atmel          at32ap700x