kfdtest: remove scc test in MapUnmapToNodes for gfx90a A+A

Modifier scc is disabled from gfx90a's asm, so remove the
shader for gfx90a A+A and keep it for newer asics with scc
support.

Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Change-Id: Iec3c7ccd5156a855adb2b02feb3db0761876aa2f

tests/kfdtest/src/ShaderStore.cpp

@@ -189,10 +189,6 @@ const char *PollMemoryIsa = R"(
  * polled can be Non-coherant memory. SCC system-level
  * cache coherence is not supported in scalar (smem) path.
  * Use vmem operations with scc
- *
- * Note: Only works on Aldebaran, and even then the scc modifier
- *       has been defeatured. This shader is more or less
- *       deprecated.
  */
 const char *PollNCMemoryIsa = R"(
         .text