src: Get rid of duplicated includes

Change-Id: I252a1cd77bf647477edb7dddadb7e527de872439
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/29582
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/arch/x86/pirq_routing.c

@@ -18,7 +18,6 @@
 #include <arch/pirq_routing.h>
 #include <string.h>
 #include <device/pci.h>
-#include <arch/pirq_routing.h>
 
 void __weak pirq_assign_irqs(const unsigned char pirq[CONFIG_MAX_PIRQ_LINKS])
 {