meru800biab: Add PM support (#253)

Summary:
# Description

This is part of a series of PRs to add support for meru800biab

This PR adds platform support and platform manager support.

#### Changes summary
- Bsp mapping; maps to the same file as meru800bia.
- Product mapping added.
- fruid.json on `fboss/oss/scripts/run_configs/j3b/fruid.json`. Although moslty identical to that of meru800bia, the product name is different and requires a new file.
- Platform manager config and eeprom fix addressed in `https://github.com/facebookexternal/fboss.bsp.arista/pull/31/files`  is applied to meru800biab

# Test

#### platform Manager
```
platform_manager[5660]: I1004 19:14:04.914047  5660 PlatformExplorer.cpp:734] Reporting firmware version for FAN_CPLD - version string:1.0 ODS value:1000
platform_manager[5660]: I1004 19:14:04.914086  5660 PlatformExplorer.cpp:734] Reporting firmware version for MERU800BIA_SMB_FPGA - version string:4.14 ODS value:4014
platform_manager[5660]: I1004 19:14:04.914118  5660 PlatformExplorer.cpp:734] Reporting firmware version for MERU_SCM_CPLD - version string:4.13 ODS value:4013
platform_manager[5660]: I1004 19:14:04.914132  5660 PlatformExplorer.cpp:657] Concluding meru800biab exploration...
systemd[1]: Started FBOSS Platform Manager.
platform_manager[5660]: I1004 19:14:04.920422  5660 Main.cpp:40] Sent sd_notify ready by running command (systemd-notify --ready)
platform_manager[5660]: I1004 19:14:04.920429  5660 Main.cpp:75] Running PlatformManager thrift service...
platform_manager[5660]: I1004 19:14:04.921137  5660 ThriftServer.cpp:836] Using thread manager (resource pools not enabled) on address/port 5975: runtime: thriftFlagNotSet, , thrift flag: false, enable gflag: false, disable gflag: false
```

Pull Request resolved: #253

Reviewed By: kimdo8736

Differential Revision: D64088064

Pulled By: joancaneus

fbshipit-source-id: cdcfc4cbf79201e10bcf4bf1b433f7a16964479b

fboss/oss/scripts/run_configs/j3b/fruid.json

@@ -0,0 +1,28 @@
+{
+  "Resources": [],
+  "Actions": [],
+  "Information": {
+    "CRC8": "0x0",
+    "Product Part Number": "",
+    "PCB Manufacturer": "",
+    "Product Sub-Version": "3",
+    "Facebook PCB Part Number": "",
+    "Product Name": "Meru800biab",
+    "Local MAC": "80:A2:35:F4:FE:5B",
+    "Facebook PCBA Part Number": "",
+    "Extended MAC Address Size": "138",
+    "Location on Fabric": "",
+    "ODM PCBA Part Number": "",
+    "Assembled At": "",
+    "System Assembly Part Number": "",
+    "Version": "3",
+    "Product Version": "6",
+    "System Manufacturing Date": "06-21-19",
+    "Product Serial Number": "",
+    "ODM PCBA Serial Number": "",
+    "Extended MAC Base": "80:A2:35:F4:FE:5C",
+    "System Manufacturer": "",
+    "Product Production State": "4",
+    "Product Asset Tag": ""
+  }
+}