ggml : set cache line size to 128 on POWER9

ggml.c

@@ -339,8 +339,12 @@ int64_t ggml_cycles_per_ms(void) {
 #if defined(__cpp_lib_hardware_interference_size)
 #define CACHE_LINE_SIZE hardware_destructive_interference_size
 #else
+#if defined(__POWER9_VECTOR__)
+#define CACHE_LINE_SIZE 128
+#else
 #define CACHE_LINE_SIZE 64
 #endif
+#endif
 
 static const size_t CACHE_LINE_SIZE_F32 = CACHE_LINE_SIZE/sizeof(float);