arm : Atmel : add at91sam9x5ek board support

Add at91sam9x5ek board support, this board support the following SoCs
  AT91SAM9G15, AT91SAM9G25, AT91SAM9G35, AT91SAM9X25, AT91SAM9X35

Using at91sam9x5ek_nandflash to configure for the board
Now only supports NAND with software ECC boot up

Signed-off-by: Bo Shen <voice.shen@atmel.com>
[move MAINTAINERS entry to right place]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/boards.cfg b/boards.cfg
index 47e0c64..6d60523 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -94,6 +94,7 @@
 at91sam9m10g45ek_nandflash   arm         arm926ejs   at91sam9m10g45ek    atmel          at91        at91sam9m10g45ek:AT91SAM9M10G45,SYS_USE_NANDFLASH
 at91sam9rlek_dataflash       arm         arm926ejs   at91sam9rlek        atmel          at91        at91sam9rlek:AT91SAM9RL,SYS_USE_DATAFLASH
 at91sam9rlek_nandflash       arm         arm926ejs   at91sam9rlek        atmel          at91        at91sam9rlek:AT91SAM9RL,SYS_USE_NANDFLASH
+at91sam9x5ek_nandflash       arm         arm926ejs   at91sam9x5ek        atmel          at91        at91sam9x5ek:AT91SAM9X5,SYS_USE_NANDFLASH
 at91sam9xeek_dataflash_cs0   arm         arm926ejs   at91sam9260ek       atmel          at91        at91sam9260ek:AT91SAM9XE,SYS_USE_DATAFLASH_CS0
 at91sam9xeek_dataflash_cs1   arm         arm926ejs   at91sam9260ek       atmel          at91        at91sam9260ek:AT91SAM9XE,SYS_USE_DATAFLASH_CS1
 at91sam9xeek_nandflash       arm         arm926ejs   at91sam9260ek       atmel          at91        at91sam9260ek:AT91SAM9XE,SYS_USE_NANDFLASH