Tested basic fastboot commands, such as:
On the U-boot prompt:
=> fastboot 0
On the host PC:
$ fastboot getvar bootloader-version -i 0x0525
bootloader-version: U-Boot 
2015.10-rc2-09654-g8f41d27
finished. total time: 0.000s
$ fastboot reboot -i 0x0525 --> board reboots fine.
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Reviewed-by: Fabio Estevam <fabio.estevam@freescale.com>
 #define CONFIG_G_DNL_PRODUCT_NUM       0xa4a5
 #define CONFIG_G_DNL_MANUFACTURER      "Congatec"
 
+#define CONFIG_USB_FUNCTION_FASTBOOT
+#define CONFIG_CMD_FASTBOOT
+#define CONFIG_ANDROID_BOOT_IMAGE
+#define CONFIG_FASTBOOT_BUF_ADDR   CONFIG_SYS_LOAD_ADDR
+#define CONFIG_FASTBOOT_BUF_SIZE   0x07000000
+
 /* Framebuffer */
 #define CONFIG_VIDEO
 #define CONFIG_VIDEO_IPUV3