comedi: fl512: Add sanity checks for I/O base address

comedi: fl512: Add sanity checks for I/O base address

The "fl512" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of an FL512
board.  It currently allows any base address to be configured and uses a
16-byte register region.

I cannot find any information about this board, but assume it needs to
be aligned to a 16-byte boundary.  I have no idea about the allowed
range, so allow anything in a 32-bit range and add a "FIXME" comment
(although most ancient ISA cards only support 10-bit address decoding).
Add a sanity check to ensure the device is not configured at an
unsupported base address.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260130170416.49994-25-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>