ich_descriptors: Don't base chipset detection on `freq_read`

Only warn if the `freq_read` setting looks odd but don't override
our previous guess. The `freq_read` check was taken from `ifdtool`
but seems less reliable than our own detection scheme.

Change-Id: I658d76ec2567d1d660a18d0b0ae71c744e603e8f
Signed-off-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/55650
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Original-Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71400
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/ich_descriptors.c b/ich_descriptors.c
index ed00896..1de4577 100644
--- a/ich_descriptors.c
+++ b/ich_descriptors.c
@@ -978,7 +978,7 @@
 	case CHIPSET_300_SERIES_CANNON_POINT:
 	case CHIPSET_GEMINI_LAKE:
 		/* `freq_read` was repurposed, so can't check on it any more. */
-		return guess;
+		break;
 	case CHIPSET_100_SERIES_SUNRISE_POINT:
 	case CHIPSET_C620_SERIES_LEWISBURG:
 	case CHIPSET_APOLLO_LAKE:
@@ -987,19 +987,17 @@
 				  "However, the read frequency isn't set to 17MHz (the only valid value).\n"
 				  "Please report this message, the output of `ich_descriptors_tool` for\n"
 				  "your descriptor and the output of `lspci -nn` to flashrom@flashrom.org\n\n");
-			return CHIPSET_9_SERIES_WILDCAT_POINT;
 		}
-		return guess;
+		break;
 	default:
 		if (component->modes.freq_read == 6) {
 			msg_pwarn("\nThe flash descriptor has the read frequency set to 17MHz. However,\n"
 				  "it doesn't look like a Skylake/Sunrise Point compatible descriptor.\n"
 				  "Please report this message, the output of `ich_descriptors_tool` for\n"
 				  "your descriptor and the output of `lspci -nn` to flashrom@flashrom.org\n\n");
-			return CHIPSET_100_SERIES_SUNRISE_POINT;
 		}
-		return guess;
 	}
+	return guess;
 }
 
 /* len is the length of dump in bytes */