message: print boot parameter if available
diff: #include <asm/irq.h>
  #include <asm/page.h>
  #include <asm/uart.h>
  +#include <asm/multiboot.h>
  #include <lwip/init.h>
  #include <lwip/sys.h>
  @@ -586,6 +587,8 @@ int hermit_main(void)
  LOG_INFO("Current available memory: %zd MiB\n", atomic_int64_read(&total_available_pages) * PAGE_SIZE / (1024ULL*1024ULL));
  LOG_INFO("Core %d is the boot processor\n", boot_processor);
  LOG_INFO("System is able to use %d processors\n", possible_cpus);
  + if (mb_info)
  + LOG_INFO("Kernel cmdline: %s\n", (char*) (size_t) mb_info->cmdline);
  if (hbmem_base)
  LOG_INFO("Found high bandwidth memory at 0x%zx (size 0x%zx)\n", hbmem_base, hbmem_size);
  