ggml : fix missing `cpu_set_t` on emscripten (#9336)

* ggml : fix missing cpu_set_t on emscripten

* better version

* bring back android part

ggml/src/ggml.c

@@ -19556,7 +19556,8 @@ static bool ggml_thread_apply_priority(int32_t prio) {
     return true;
 }
 
-#else // posix?
+#elif defined(__gnu_linux__)
+// TODO: this may not work on BSD, to be verified
 
 static bool ggml_thread_apply_affinity(const bool * mask) {
     cpu_set_t cpuset;
@@ -19611,6 +19612,18 @@ static bool ggml_thread_apply_priority(int32_t prio) {
     return true;
 }
 
+#else // unsupported platforms
+
+static bool ggml_thread_apply_affinity(const bool * mask) {
+    UNUSED(mask);
+    return true;
+}
+
+static bool ggml_thread_apply_priority(int32_t prio) {
+    UNUSED(prio);
+    return true;
+}
+
 #endif
 
 static bool ggml_thread_cpumask_is_valid(const bool * mask) {