Revert "serial: uartps: Change uart ID port allocation"

This reverts commit ae1cca3f.

With setting up NR_PORTS to 16 to be able to use serial2 and higher
aliases and don't loose functionality which was intended by these changes.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost



Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/a94931b65ce0089f76fb1fe6b446a08731bff754.1585905873.git.michal.simek@xilinx.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>