mainboard/**/irq_tables.c: Remove reference to getpir

The obsolete and removed getpir utility remarked in its output that the
data is autogenerated. The tool was removed because it wasn't very
reliable, so there's no need to point that anymore.

Change-Id: I5d624931ba7872b1fefa8fa3c270ae7367e069fa
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/12354
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

src/mainboard/emulation/qemu-i440fx/irq_tables.c

@@ -1,10 +1,3 @@
-/* This file was generated by getpir.c, do not modify!
-   (but if you do, please run checkpir on it to verify)
- * Contains the IRQ Routing Table dumped directly from your memory, which BIOS sets up
- *
- * Documentation at : http://www.microsoft.com/hwdev/busbios/PCIIRQ.HTM
-*/
-
 #include <arch/pirq_routing.h>
 
 static const struct irq_routing_table intel_irq_routing_table = {