wusb: remove unused #include <version.h>

The file(s) below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/usb/host/hwa-hc.c
  drivers/usb/host/whci/hcd.c
  drivers/usb/host/whci/int.c
  drivers/usb/host/whci/wusb.c
  drivers/usb/wusbcore/cbaf.c

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

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David Vrabel <david.vrabel@csr.com>