iwlwifi: cleanup namespace

Prefix all symbols with iwl3945_ or iwl4965_ and thus allow building
the driver into the kernel. Also remove all the useless default
statements in Kconfig while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>