Set default flags nvcc and do not set default compile flags for ROCM EP (#19124)
### Description
Set default flags nvcc and do not set the flags for ROCM EP.
### Motivation and Context
1. To meet a BinSkim requirement for CUDA EP.
https://github.com/microsoft/binskim/blob/main/docs/BinSkimRules.md#rule-BA2024EnableSpectreMitigations
2. The ROCM EP's pipeline is broken since PR #19073 . Unit tests failed
to load the EP with the following error message:
Failed to load library libonnxruntime_providers_rocm.so with error:
/build/Release/libonnxruntime_providers_rocm.so: undefined symbol:
vtable for onnxruntime::InsertMaxPoolOutput .
This PR is a hot fix to bring the pipeline back. So far I don't know why
the error happened. The symbol "InsertMaxPoolOutput" is in
onnxruntime_optimizers. I don't see any EP code references it directly.