Remove use of vendor specific macros

[bluecmd]

SAI should not care about which vendor is loaded, so remove the compile time requirement to specify which vendor will be.

Proposal from discussions in #1972

[kcudnik]

pleasse add authors of code that is being removed to disscuss whether this is safe

[bluecmd]

pleasse add authors of code that is being removed to disscuss whether this is safe

Sure, looking at older PRs I guess this is @chrispsommers and @richardyu-ms.

I hope this ping is sufficient to ask for a review :-)

[richardyu-ms]

did you make test with your changes in different platforms, meanwhile did you run those change in build-image repo?
Indeed, we expect the SAI module does not depend on vendors, but when SAI module build on different vendor platform it related to different SAI implementation/driver, then there we might need different build parameters to build SONiC image with different SAI implementations from different vendors

[bluecmd]

I have tested this successfully on Broadcom and Innovium SAI.

[richardyu-ms]

I have tested this successfully on Broadcom and Innovium SAI.

Cause in your changes, there are some changes to remove the build parameters across many platforms

ifeq ($(platform),MLNX)
CDEFS = -DMLNXSAI
else
ifeq ($(platform),BFT)
CDEFS = -DBFTSAI
else
ifeq ($(platform),CAVIUM)
CDEFS = -DCAVIUMSAI
else
CDEFS = -DBRCMSAI
endif
endif
endif

I think it is better to build the image with your code on those platforms at least, it can make sure the sai component will not impact the SONiC image build.

[bluecmd]

@richardyu-ms I do not have any possibility of testing all those platforms.

It seems to me that this code is dead and unmaintained, and I would be surprised if anyone with Barefoot or Cavium runs this code.

If you are certain you require testing on these platforms to remove this code, I will be forced to give up on this PR.

[..] it can make sure the sai component will not impact the SONiC image build.

Is the saithrift component really used in SONiC? I thought it was only used internally in SAI for tests.