pata_hpt366: fix cable detection,

pata_hpt366 is strange in that its two channels occupy two PCI
functions and both are primary channels and bit1 of PCI configuration
register 0x5A indicates cable for both channels.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>