staging/lustre/lnet: Move asm/irq.h include after linux includes

Apparently m86k cannot build if you include asm/irq.h before
linux/* includes and fixing it there is hard.
So just move asm/irq.h include to where it does not cause any problems.

Thanks to Geert Uytterhoeven for getting to the root of it.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Compile-Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>