NS16550A: Restore HS settings in EXCR2 on resume

NS16550A: Restore HS settings in EXCR2 on resume

After a suspend/resume cycle, the UART may have been reset into
low-speed mode -- either because it's actually been reset, or because
the firmware pokes at the old-style divisor registers. If we detected it
as a NS16550A SuperIO chip in the first place and set baud_base to
921600, then we should do so again in the resume path.

This patch adds that code to serial8250_resume_port(), and also makes
serial8250_resume() actually call serial8250_resume_port() for each port
instead of just calling uart_resume_port() directly. And thus fixes
serial port operation after suspend/resume.

It also fixes a bogus comment where we write the EXCR2 register with a
comment saying /* EXCR1 */

Signed-off-by: David Woodhouse <[email protected]>
Acked-by: Alan Cox <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>