[llvm] [AMDGPU][NFC] Update test to use update_llc_test_checks (PR #178826)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

In a follow up this test could use more modernization. Like dropping -amdgpu-scalarize-global-loads=false, and rewriting to avoid use of kernels and instead rely on inreg for SGPR inputs 

https://github.com/llvm/llvm-project/pull/178826