wifi: ipw2x00: Remove unused libipw_rx_any()

libipw_rx_any() was added in 2006 by commit 1a995b45 ("[PATCH]
ieee80211_rx_any: filter out packets, call ieee80211_rx or ieee80211_rx_mgt")
as ieee80211_rx_any but is currently unused and I can't find any sign it was
used under either name.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20250122022240.456198-1-linux@treblig.org