nb/intel/haswell: Fix IOMMU early init

Intel Document 492662 (Haswell System Agent BIOS Spec), Rev 1.6.0 states
that `ARCHDIS` (VT engine BAR, offset 0xff0) has to be written fully, as
well as several other things that were not done properly in coreboot. As
these steps are Haswell-specific, introduce two helper functions to test
if the CPU is Haswell or Broadwell.

Intel Document 535094 (Broadwell BIOS Spec), Rev 2.2.0 contains the same
steps for Broadwell. To permit unifying Haswell and Broadwell, implement
the Broadwell steps as well.

Change-Id: I077e064754720d9f9f627733c954712a2b24b5b7
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91631
Reviewed-by: Alicja Michalska <ahplka19@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>

src/cpu/intel/haswell/haswell.h

@@ -192,4 +192,27 @@ static inline bool haswell_is_ult(void)
 	return CONFIG(INTEL_LYNXPOINT_LP);
 }
 
+static inline bool cpu_is_haswell(void)
+{
+	switch (cpu_family_model()) {
+	case HASWELL_FAMILY_TRAD:
+	case HASWELL_FAMILY_ULT:
+	case CRYSTALWELL_FAMILY:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline bool cpu_is_broadwell(void)
+{
+	switch (cpu_family_model()) {
+	case BROADWELL_FAMILY_TRAD:
+	case BROADWELL_FAMILY_ULT:
+		return true;
+	default:
+		return false;
+	}
+}
+
 #endif