southbridge/intel/common: Move invalid PIRQ value to 0

This makes structs that contain an `enum pirq` field that is
default-initialized have the value PIRQ_INVALID

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Idb4c7d79de13de0e4b187a42e8bdb27e25e61cc1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55281
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/common/block/lpc/lpc_lib.c b/src/soc/intel/common/block/lpc/lpc_lib.c
index 1b6936e..0268245 100644
--- a/src/soc/intel/common/block/lpc/lpc_lib.c
+++ b/src/soc/intel/common/block/lpc/lpc_lib.c
@@ -293,14 +293,14 @@
 }
 
 static const uint8_t pch_interrupt_routing[PIRQ_COUNT] = {
-	[PIRQ_A] = PCH_IRQ11,
-	[PIRQ_B] = PCH_IRQ10,
-	[PIRQ_C] = PCH_IRQ11,
-	[PIRQ_D] = PCH_IRQ11,
-	[PIRQ_E] = PCH_IRQ11,
-	[PIRQ_F] = PCH_IRQ11,
-	[PIRQ_G] = PCH_IRQ11,
-	[PIRQ_H] = PCH_IRQ11,
+	[0] = PCH_IRQ11,	/* PIRQ_A */
+	[1] = PCH_IRQ10,	/* PIRQ_B */
+	[2] = PCH_IRQ11,	/* PIRQ_C */
+	[3] = PCH_IRQ11,	/* PIRQ_D */
+	[4] = PCH_IRQ11,	/* PIRQ_E */
+	[5] = PCH_IRQ11,	/* PIRQ_F */
+	[6] = PCH_IRQ11,	/* PIRQ_G */
+	[7] = PCH_IRQ11,	/* PIRQ_H */
 };
 
 const uint8_t *lpc_get_pic_pirq_routing(size_t *num)