allow scaling the quantum_limit to 65536

Make it possible to change the quantum-limit in the config file past
8192 up to 65536. This will make all plugins allocate larger buffers
so that the quantum can be increased to larger values as well,

This is interesting when dealing with higher sample rates where the
8192 sample limit will cause wakeups every 20ms at 384KHz.

See #1931

src/pipewire/private.h

@@ -51,7 +51,7 @@ struct ucred {
 
 #define MAX_RATES				16u
 #define CLOCK_MIN_QUANTUM			4u
-#define CLOCK_MAX_QUANTUM			8192u
+#define CLOCK_MAX_QUANTUM			65536u
 
 struct settings {
 	uint32_t log_level;