ide/libata: fix ata_id_is_cfa() (take 4)

ide/libata: fix ata_id_is_cfa() (take 4)

When checking for the CFA feature set support, ata_id_is_cfa() tests bit 2 in
word 82 of the identify data instead the word 83;  it also checks the ATA/PI
version support in the word 80 (which the CompactFlash specifications have as
reserved), this having no slightest chance to work on the modern CF cards that
don't have 0x848A in the word 0...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>