[netdrvr] Remove Becker-template 'io_size' member, when invariant

Becker-derived drivers often have the 'io_size' member in their chip
info struct, indicating the minimum required size of the I/O resource
(usually a PCI BAR).  For many situations, this number is either
constant or irrelevant (due to pci_iomap convenience behavior).

This change removes the io_size invariant member, and replaces it with a
compile-time constant.

Drivers updated: fealnx, gt96100eth, winbond-840, yellowfin

Additionally,
- gt96100eth: unused 'drv_flags' removed from gt96100eth
- winbond-840: unused struct match_info removed
- winbond-840: mark pci_id_tbl[] const, __devinitdata

Signed-off-by: Jeff Garzik <jeff@garzik.org>