arch: Change defconfigs to point to g_mass_storage.

The File-backed Storage Gadget (g_file_storage) is being removed, since
it has been replaced by Mass Storage Gadget (g_mass_storage).  This commit
changes defconfigs point to the new gadget.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>  (AT91)
Acked-by: Tony Lindgren <tony@atomide.com>  (OMAP1)
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> (AVR32)
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/arch/arm/configs/viper_defconfig b/arch/arm/configs/viper_defconfig
index 1d01ddd..d36e0d3 100644
--- a/arch/arm/configs/viper_defconfig
+++ b/arch/arm/configs/viper_defconfig
@@ -139,7 +139,7 @@
 CONFIG_USB_GADGET=m
 CONFIG_USB_ETH=m
 CONFIG_USB_GADGETFS=m
-CONFIG_USB_FILE_STORAGE=m
+CONFIG_USB_MASS_STORAGE=m
 CONFIG_USB_G_SERIAL=m
 CONFIG_USB_G_PRINTER=m
 CONFIG_RTC_CLASS=y