wireless: remove unused #include <version.h>

The driver(s) below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/net/wireless/b43legacy/main.c
  drivers/net/wireless/iwlwifi/iwl-3945-led.c
  drivers/net/wireless/iwlwifi/iwl-led.c
  drivers/net/wireless/iwlwifi/iwl-rfkill.c

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

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>