wifi: remove orphaned orinoco driver

Orinoco is a PIO-only ISA/PCMCIA 802.11b device with extra bus interface
connections for PCI/Cardbus/mini-PCI and a few pre-2002 Apple PowerMac
variants. It supports both wireless extensions and CFG80211, but I could
not tell if it requires using both.

This device used to be one of the most common ones 20 years ago, but
has been orphaned for most of the time since then, and the conversion
to cfg80211 has stalled in 2010.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@kernel.org>