ata: pata_legacy: remove VLB support

ata: pata_legacy: remove VLB support

This significantly reduces the complexity of the pata_legacy driver.
The VLB bus is very obsolete and last appeared on P5 Pentium-era
hardware. Support for it has been removed from other drivers, and
it is highly unlikely anyone is using it with modern Linux kernels.
Some of these chips were integrated on motherboards, but they
seem to have all been 486-era boards, which are equally obsolete.

Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>