Revert "serial: 8250: Switch to nbcon console"

Revert "serial: 8250: Switch to nbcon console"

This reverts commit b63e6f60eab45b16a1bf734fef9035a4c4187cd5.

kernel test robot has found problems with this commit so revert it for
now.

Link: https://lore.kernel.org/r/202501221029.fb0d574d-lkp@intel.com
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202501221029.fb0d574d-lkp@intel.com
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>