RiOTboard and MarSBoard: add new boards support

RiOTboard is produced by Embest/Element 14 and is based on i.MX6 Solo
The following features are tested :
- UART2 (console)
- eMMC
- SDCard
- uSDCard
- Ethernet
- USB Host (through 4 ports hub)
- HDMI output
- I2C 1/2/3
- LVDS TFT with LCD8000-97C from Embest/Element 14

Boot on eMMC and through USB loader are tested.

For more informations on this board : http://www.riotboard.org/

MarSBoard is produced by Embest/Element 14 and is based on i.MX6 Dual
The following features are tested :
- UART2 (console)
- eMMC
- uSDCard
- Ethernet
- USB Host (through 2 ports hub)
- HDMI output
- I2C 1/2
- SPI NOR Flash
- LVDS TFT with LCD8000-97C from Embest/Element 14

Boot on SPI NOR and through USB loader are tested.

For more informations on this board :
http://www.embest-tech.com/shop/star/marsboard.html

Both boards are supported by the same code base as they are based on a
common trunk of schematics.

Signed-off-by: Eric BĂ©nard <eric@eukrea.com>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/boards.cfg b/boards.cfg
index b4203f1..9a87aa7 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -328,6 +328,8 @@
 Active  arm         armv7          mx6         gateworks       gw_ventana          gwventanaq1g                         gw_ventana:IMX_CONFIG=board/gateworks/gw_ventana/gw_ventana.cfg,MX6Q,DDR_MB=1024                                                  Tim Harvey <tharvey@gateworks.com>
 Active  arm         armv7          mx6         gateworks       gw_ventana          gwventanaq1gspi                      gw_ventana:IMX_CONFIG=board/gateworks/gw_ventana/gw_ventana.cfg,MX6Q,DDR_MB=1024,SPI_FLASH                                        Tim Harvey <tharvey@gateworks.com>
 Active  arm         armv7          mx6         solidrun        hummingboard        hummingboard_solo                    hummingboard:IMX_CONFIG=board/solidrun/hummingboard/solo.cfg,MX6S,DDR_MB=512                                                      Jon Nettleton <jon.nettleton@gmail.com>
+Active  arm         armv7          mx6         embest          mx6boards           riotboard                            embestmx6boards:IMX_CONFIG=board/boundary/nitrogen6x/nitrogen6s1g.cfg,MX6S,DDR_MB=1024,ENV_IS_IN_MMC                              Eric Bénard <eric@eukrea.com>
+Active  arm         armv7          mx6         embest          mx6boards           marsboard                            embestmx6boards:IMX_CONFIG=board/boundary/nitrogen6x/nitrogen6q.cfg,MX6Q,DDR_MB=1024,ENV_IS_IN_SPI_FLASH                          Eric Bénard <eric@eukrea.com>
 Active  arm         armv7          omap3       -               overo               omap3_overo                          -                                                                                                                                 Steve Sakoman <sakoman@gmail.com>
 Active  arm         armv7          omap3       -               pandora             omap3_pandora                        -                                                                                                                                 Grazvydas Ignotas <notasas@gmail.com>
 Active  arm         armv7          omap3       8dtech          eco5pk              eco5pk                               -                                                                                                                                 Raphael Assenat <raph@8d.com>