corstone1000: enable isp1763 usb controller and mmc

MPS3 board have a ISP1763 usb controller, enable it to be used
for mass storage access for example. Enable the usb command
also and for the FVP support for mass storage enable the mmc
command.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
diff --git a/include/configs/corstone1000.h b/include/configs/corstone1000.h
index 38d7fe8..8e0230c 100644
--- a/include/configs/corstone1000.h
+++ b/include/configs/corstone1000.h
@@ -24,4 +24,10 @@
 
 #define CONFIG_SYS_SDRAM_BASE	PHYS_SDRAM_1
 
+#define BOOT_TARGET_DEVICES(func) \
+	func(USB, usb, 0)
+
+#include <config_distro_bootcmd.h>
+
+
 #endif