removed unused #include <version.h>

The drivers below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/net/wireless/ath5k/base.c
  drivers/net/wireless/b43/main.c
  drivers/net/wireless/ipw2100.c
  drivers/net/wireless/ipw2200.c
  drivers/net/wireless/iwlwifi/iwl-3945.c
  drivers/net/wireless/iwlwifi/iwl-4965.c
  drivers/net/wireless/iwlwifi/iwl-5000.c
  drivers/net/wireless/iwlwifi/iwl-agn.c
  drivers/net/wireless/iwlwifi/iwl-core.c
  drivers/net/wireless/iwlwifi/iwl-eeprom.c
  drivers/net/wireless/iwlwifi/iwl-hcmd.c
  drivers/net/wireless/iwlwifi/iwl-power.c
  drivers/net/wireless/iwlwifi/iwl3945-base.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>