Staging: wlags49_h2, wlags49_h25: fixed Kconfig dependencies

Fixes Kconfig so the wlags49_h2 and wlags49_h25 drivers can be
selected from menuconfig without having to select another WLAN
driver first. Before it could only be selected when another driver
already selected WIRELESS_EXT. Also adds WEXT_PRIV on which
the driver also depends.

Align help text in Kconfig.

Signed-off-by: Henk de Groot <pe1dnn@amsat.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>