package: usbgadget: Require kmod-fs-configfs

package: usbgadget: Require kmod-fs-configfs

The usbgadget package tries to mount and use configfs so it
needs to require the kernel module instead of implying it.

There should be a newline at the end of the file as well.

Link: http://patchwork.ozlabs.org/project/openwrt/patch/[email protected]/
Reviewed-by: Chuanhong Guo <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>