[AMDGPU] Rename COV module flag to amdhsa_code_object_version (#79905)

The previous name 'amdgpu_code_object_version', was misleading since
this is really a property of the HSA OS. The new spelling also matches
the asm directive I added in bc82cfb.

GitOrigin-RevId: 4490003a22658dcd12527029b2c8682b63d8a9d6
diff --git a/test/ELF/lto/amdgcn-oses.ll b/test/ELF/lto/amdgcn-oses.ll
index 0fd0ce4..7a74d03 100644
--- a/test/ELF/lto/amdgcn-oses.ll
+++ b/test/ELF/lto/amdgcn-oses.ll
@@ -28,7 +28,7 @@
 target datalayout = "e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5"
 
 !llvm.module.flags = !{!0}
-!0 = !{i32 1, !"amdgpu_code_object_version", i32 500}
+!0 = !{i32 1, !"amdhsa_code_object_version", i32 500}
 
 define void @_start() {
   ret void