for 1-bit lower inner dimension need to go slower path to avoid bug

Author: khosravipasha

mlx/backend/metal/quantized.cpp

@@ -1282,7 +1282,7 @@ void dispatch_qmv(
     const Stream& s,
     const std::string& mode) {
   // It is a qmv with a small inner dimension so route to qmv_quad kernel
-  if ((K == 128 || K == 64) && is_power_of_2(bits)) {
+  if ((K == 128 || (K == 64 && bits >= 2)) && is_power_of_2(bits)) {
     qmv_quad(x, w, scales, biases, out, group_size, bits, M, N, K, d, s, mode);
     return;
   }