The aironet PCI driver has a build dependency on ISA that prevent the
driver to compile on systems that doesn't support ISA, like x86_64. The
driver really doesn't depend on ISA, it does some ISA stuff in the
initialization code, since the driver supports both ISA and PCI cards. So
the driver should depend on ISA_DMA_API to build on all systems, and this
will not hurt PCI at all.