This patch brings the airo driver into line with the current
WEXT specification of signal quality.  It also fixes the values
used to determine signal quality and level for MPI & PCMCIA 350
cards.  It turns out that BSSListRid.rssi was actually in dBm
for 350 series cards, and that we can use the normalized
signal strength reported by the card as our "quality" value, on
a scale of 0 - 100.  Since signal level values are in dBm for
this driver, max_qual->level MUST be 0, as specified in the WEXT
spec.  This patch also uses the IW_QUAL constants new in WEXT
version 17.
Signed-off-by: Dan Williams <dcbw@redhat.com>