phone: Scale cpu frequency down 3 levels

Was crashing way too often with max frequency so hopefully having the
frequency slightly above half the maximum speed makes things more
stable.

hosts/phone/configuration.nix

@@ -200,7 +200,7 @@ in
     enable = true;
 
     cpufreq = rec {
-      min = 1152000;
+      min = 1008000;
       max = min;
     };