hamradio: use ndo_siocdevprivate

hamradio uses a set of private ioctls that do seem to work
correctly in compat mode, as they only rely on the ifr_data
pointer.

Move them over to the ndo_siocdevprivate callback as a cleanup.

Cc: Thomas Sailer <t.sailer@alumni.ethz.ch>
Cc: Joerg Reuter <jreuter@yaina.de>
Cc: Jean-Paul Roubelat <jpr@f6fbb.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>