flashy: Add support for 128M fb-meta

Summary: As title. This is to support platforms with larger flashes and images. Fixes oobgrader failure on gtartemis which has started to go beyond the 32M size.

Test Plan:
oobgrader on gtartemis which is 128M Flash.
```
oobgrader --host gtartemis-test-host -b openbmc.image.gtartemis:v2023.32.0 --flashy-tag  6746cb7 --wait
<snip>
<snip>  c4746030-d209-4d88-b9de-18cee673c8f2  finished    WorkflowStatus.FINISHED  FinishStatus.SUCCEEDED
```
Workflow ID: c4746030-d209-4d88-b9de-18cee673c8f2

Ensure no regressions are observed in older ones.
```
oobgrader --host fby3-test-host -b openbmc.image.yosemite3:v2023.13.1 --flashy-tag 6746cb7  --wait
<snip>
<snip>  b4524080-d79d-4ef2-a7e8-7fc97b224a0f  finished    WorkflowStatus.FINISHED  FinishStatus.SUCCEEDED
```
Workflow ID: b4524080-d79d-4ef2-a7e8-7fc97b224a0f

Reviewed By: cjcon90

Differential Revision: D48207387

fbshipit-source-id: f0f349b9ab237a439c8f0088da573cff141828b9

Author: amithash

tools/flashy/lib/validate/partition/config.go

@@ -65,6 +65,20 @@ type PartitionConfigInfo struct {
 // (4) vboot spl+recovery can be treated as UBOOT. It will be ignored if the flash1
 //     header is RO (e.g. fbtp)
 var ImageFormats = []ImageFormat{
+	{
+		// covers both vboot-meta and fit-meta
+		Name: "meta-big",
+		PartitionConfigs: []PartitionConfigInfo{
+			{
+				// pass in the whole image and let MetaImagePartition deal with
+				// finding the partitionConfigs and checksums
+				Name:   "fbmeta-image-big",
+				Offset: 0,
+				Size:   128 * 1024 * 1024,
+				Type:   FBMETA_IMAGE,
+			},
+		},
+	},
 	{
 		// covers both vboot-meta and fit-meta
 		Name: "meta",