[llvm] Fix to account for multiple ISA enumeration (PR #118676)

[Shilei Tian via llvm-commits]

shiltian wrote:

> Not the OpenMP level, we need one at the ELF flags level.

The generic ELF has to match generic ISA provided by HSA. There is no need to do that at the ELF flag level. For example, if the ELF is `gfx10-3-generic`, it should _not_ work with `gfx1030`, at least not based on the design of HSA.

https://github.com/llvm/llvm-project/pull/118676