prism54: remove private driver ioctls

As of hostap_0_7_1~358 the CONFIG_DRIVER_PRISM54
was removed from upstream wpa_supplicant/hostapd so
lets just kill the useless old prism54 private ioctl
crap.

Cc: Jouni Malinen <j@w1.fi>
Cc: David Miller <davem@davemloft.net>
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>