tty: 8250: Add support for Intashield IX cards

commit 62d2ec2d

 upstream.

Add support for the IX-100, IX-200 and IX-400 serial cards.

Cc: stable@vger.kernel.org
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DU0PR02MB7899614E5837E82A03272A4BC4DBA@DU0PR02MB7899.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>