USB: remove unused #include <version.h>

The driver(s) below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/usb/gadget/pxa27x_udc.c

This patch removes the said #include <version.h>.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>