compat_ioctl: move isdn/capi ioctl translation into driver

Neither the old isdn4linux interface nor the newer mISDN stack
ever had working 32-bit compat mode as far as I can tell.

However, the CAPI stack has some ioctl commands that are
correctly listed in fs/compat_ioctl.c.

We can trivially move all of those into the corresponding
file that implement the native handlers by adding a compat_ioctl
redirect to that.

I did notice that treating CAPI_MANUFACTURER_CMD() as compatible
is broken, so I'm also adding a handler for that, realizing that
in all likelyhood, nobody is ever going to call it.

Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Cc: isdn4linux@listserv.isdn4linux.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>