[llvm] AMDGPU: Add gfx1250 to sram-ecc elf header flags test (PR #162107)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> We didn't mark sramecc as a supported feature in `llvm/lib/TargetParser/TargetParser.cpp`.

TargetParser isn't the source of truth, that's just a random sample of stuff exported to clang. The feature is still there on the processor 

https://github.com/llvm/llvm-project/pull/162107