comedi: add comedi_check_request_region()

comedi: add comedi_check_request_region()

There is an existing comedi_request_region(dev, start, len) function
used by COMEDI drivers for legacy devices to request an I/O port region
starting at a specified base address (which must be non-zero) and with a
specified length.  It uses request_region().  On success, it sets
dev->iobase and dev->iolen and returns 0.  There is a alternative
function __comedi_request_region(dev, start, len) which does the same
thing without setting dev->iobase and dev->iolen.

Most hardware devices have restrictions on the allowed I/O port base
address and alignment, so add new functions
comedi_check_request_region(dev, start, len, minstart, maxend, minalign)
and __comedi_check_request_region(dev, start, len, minstart, maxend,
minalign) to perform these additional checks.  Turn the original
functions into static inline wrapper functions that call the new
functions.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260130170416.49994-2-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>