#### Why I did it
Add platform_asic file to each platform folder in sonic-device-data package. The file content will be used as the ground truth of mapping from PLATFORM_STRING to switch ASIC family.
One use case of the mapping is to prevent installing a wrong image, which targets for other ASIC platforms. For example, currently we have several ONIE images naming as sonic-*.bin, it's easy to mistakenly install the wrong image. With this mapping built into image, we could fetch the ONIE platform string, and figure out which ASIC it is using, and check we are installing the correct image.
After this PR merged, each platform vendor has to add one mandatory text file `device/PLATFORM_VENDOR/PLATFORM_STRING/platform_asic`, with the content of the platform's switch ASIC family.
I will update https://github.com/Azure/SONiC/wiki/Porting-Guide after this PR is merged.
You can get a list of the ASIC platforms by `ls -b platform | cat`. Currently the options are
```
barefoot
broadcom
cavium
centec
centec-arm64
generic
innovium
marvell
marvell-arm64
marvell-armhf
mellanox
nephos
p4
vs
```
Also support
```
broadcom-dnx
```
#### How I did it
#### How to verify it
Test one image on DUT. And check the folders under `/usr/share/sonic/device`
Submodule updates include the following commits:
* src/sonic-utilities 9dc58ea...f9eb739 (18):
> Remove unnecessary calls to str.encode() now that the package is Python 3; Fix deprecation warning (#1260)
> [generate_dump] Ignoring file/directory not found Errors (#1201)
> Fixed porstat rate and util issues (#1140)
> fix error: interface counters is mismatch after warm-reboot (#1099)
> Remove unnecessary calls to str.decode() now that the package is Python 3 (#1255)
> [acl-loader] Make list sorting compliant with Python 3 (#1257)
> Replace hard-coded fast-reboot with variable. And some typo corrections (#1254)
> [configlet][portconfig] Remove calls to dict.has_key() which is not available in Python 3 (#1247)
> Remove unnecessary conversions to list() and calls to dict.keys() (#1243)
> Clean up LGTM alerts (#1239)
> Add 'requests' as install dependency in setup.py (#1240)
> Convert to Python 3 (#1128)
> Fix mock SonicV2Connector in python3: use decode_responses mode so caller code will be the same as python2 (#1238)
> [tests] Do not trim from PATH if we did not append to it; Clean up/fix shebangs in scripts (#1233)
> Updates to bgp config and show commands with BGP_INTERNAL_NEIGHBOR table (#1224)
> [cli]: NAT show commands newline issue after migrated to Python3 (#1204)
> [doc]: Update Command-Reference.md (#1231)
> Added 'import sys' in feature.py file (#1232)
* src/sonic-py-swsssdk 9d9f0c6...1664be9 (2):
> Fix: no need to decode() after redis client scan, so it will work for both python2 and python3 (#96)
> FieldValueMap `contains`(`in`) will also work when migrated to libswsscommon(C++ with SWIG wrapper) (#94)
- Also fix Python 3-related issues:
- Use integer (floor) division in config_samples.py (sonic-config-engine)
- Replace print statement with print function in eeprom.py plugin for x86_64-kvm_x86_64-r0 platform
- Update all platform plugins to be compatible with both Python 2 and Python 3
- Remove shebangs from plugins files which are not intended to be executable
- Replace tabs with spaces in Python plugin files and fix alignment, because Python 3 is more strict
- Remove trailing whitespace from plugins files
