Would I be violating the GPL?

[Alexander Fisher <alexjfisher@gmail.com>]

Hello.

A supplier of a PCI mezzanine digital IO card has provided a linux 2.4
driver as source code.  They have provided this code source with a
license stating I won't redistribute it in anyway.
My concern is that if I build this code into a module, I won't be able
to distribute it to customers without violating either the GPL (by not
distributing the source code), or the proprietary source code license
as currently imposed by the supplier.
>From what I have read, this concern is only valid if the binary module
is considered to be a 'derived work' of the kernel.  The module source
directly includes the following kernel headers :

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/wrapper.h>
#include <linux/module.h>
#include <linux/iobuf.h>
#include <linux/highmem.h>
#include <asm/uaccess.h>
#include <linux/mm.h>
#include <asm/unistd.h>

Does this make the compiled module a derived work?  Are the 'static
inlines' from the headers substantial enough?

I really want to have a clear understanding of the issues before
contacting the supplier.  Any advice would be very much appreciated.
Kind regards,
Alex