x86_64: add pre-processor token to control hardware rng

arch/x86_64/init.c

@@ -20,6 +20,8 @@
 #include <kernel/util.h>
 #include <kernel/vm.h>
 
+#undef HARDWARE_RNG
+
 #define PTR32(x)            ((void *)((uintptr_t)(x)))
 
 /* the physical address of the start of the memblock heap.
@@ -125,17 +127,21 @@ int ml_init(uintptr_t arg)
 		reserve_end = bsp.mod_base + bsp.mod_size;
 	}
 
+#if defined(HARDWARE_RNG)
 	if (ml_hwrng_available()) {
 		printk("cpu: ardware RNG available");
 		uint64_t seed = ml_hwrng_generate();
 		printk("cpu: RNG seed=%zx", seed);
 		init_random(seed);
 	} else {
+#endif
 		printk("cpu: hardware RNG unavailable");
 		uint64_t seed = 0xeddc4c8a679dc23f;
 		printk("cpu: RNG seed=%zx", seed);
 		init_random(seed);
+#if defined(HARDWARE_RNG)
 	}
+#endif
 
 	early_vm_init(reserve_end);