kfdtest: Fix InterruptRestore randomly hang

Queue 2's wave blocked the queue 1's wave save, which will cause unmap
queue preemption fail. Add nop per SQ suggested.

Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Change-Id: Iea7f280e35487059c4499ea999b9e0cdf841d1e1


[ROCm/ROCR-Runtime commit: f047f96161]

projects/rocr-runtime/libhsakmt/tests/kfdtest/src/ShaderStore.cpp

@@ -161,6 +161,7 @@ const char *InfiniteLoopIsa =
     R"(
         .text
         LOOP:
+        s_nop 0x10
         s_branch LOOP
         s_endpgm
 )";