Kernel: Make aarch64 UART::print_num() print u64s

Author: https://github.com/nico
Commit: https://github.com/SerenityOS/serenity/commit/2c0d329bf60
Pull-request: https://github.com/SerenityOS/serenity/pull/10319
Reviewed-by: https://github.com/linusg ✅

Kernel/Prekernel/Arch/aarch64/UART.h

@@ -26,9 +26,9 @@ public:
         while (*s)
             send(*s++);
     }
-    void print_num(u32 n)
+    void print_num(u64 n)
     {
-        char buf[11];
+        char buf[21];
         int i = 0;
         do {
             buf[i++] = (n % 10) + '0';