soc/intel/meteorlake: Set DTT PCI device IRQ to INT_A/PIRQ_A

The Dynamic Tuning Technology (DTT) device IRQ is not programmable and
is INT_A/PIRQ_A (IRQ 16).

Reference: Meteor Lake U/H and U Type4 External Design Specification
External Design Document (657165)

TEST=Linux driver successfully uses IRQ 16 on rex. Without this patch
     it was binding IRQ 18 but interrupts were going to IRQ 16.

Change-Id: I2cbb9dd41f27c40a29346be325bb9c46d1061afb
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78953
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/soc/intel/meteorlake/fsp_params.c

@@ -63,7 +63,9 @@ static const struct slot_irq_constraints irq_constraints[] = {
 	{
 		.slot = PCI_DEV_SLOT_DPTF,
 		.fns = {
-			ANY_PIRQ(PCI_DEVFN_DPTF),
+			/* Dynamic Tuning Technology (DTT) device IRQ is not
+			   programmable and is INT_A/PIRQ_A (IRQ 16) */
+			FIXED_INT_PIRQ(PCI_DEVFN_DPTF, PCI_INT_A, PIRQ_A),
 		},
 	},
 	{