3com: Fix drivers/net/ethernet/3com/Kconfig references to PCMCIA and 3c515

The Vortex driver works with PCI and Cardbus devices, not PCMCIA.

There never was an EISA 3c515 card, only ISA, so remove that option.

Signed-off-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>