ich_descriptors: Hard code number of masters for newer gens

The number of masters (NM) field is ignored by the hardware and often
not updated in Intel's tooling.  Since PCH100 / Skylake,  it's always
been 2 masters for the small core, 5 for the big core,  and 6 for the
server platforms.

Change-Id: I4975f5b55981791fa5b10c4731af8f330cbbefa8
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/185
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/ich_descriptors.c b/ich_descriptors.c
index f24d353..dfc1cb8 100644
--- a/ich_descriptors.c
+++ b/ich_descriptors.c
@@ -71,13 +71,14 @@
 {
 	switch (cs) {
 	case CHIPSET_C620_SERIES_LEWISBURG:
+		return 6;
 	case CHIPSET_APOLLO_LAKE:
 	case CHIPSET_GEMINI_LAKE:
 	case CHIPSET_ELKHART_LAKE:
-		if (cont->NM <= MAX_NUM_MASTERS)
-			return cont->NM;
-		break;
+		return 2;
 	default:
+		if (cs >= SPI_ENGINE_PCH100)
+			return 5;
 		if (cont->NM < MAX_NUM_MASTERS)
 			return cont->NM + 1;
 	}