serial: Replace driver usage of UPF_CONS_FLOW

serial: Replace driver usage of UPF_CONS_FLOW

Rather than using the UPF_CONS_FLOW bit of uart_port.flags to track
the user configuration of console flow control, use the newly added
uart_port.cons_flow (via its getter/setter functions).

A coccinelle script was used to perform the search/replace.

Note1: The sh-sci driver is blindly copying platform data configuration
       flags to uart_port.flags. Thus UPF_CONS_FLOW could get set for
       uart_port.flags. A follow-up commit will address this.

Note2: The samsung_tty driver is using UPF_CONS_FLOW as a platform data
       configuration flag. However, the driver explicitly checks for
       this configuration flag and thus setting UPF_CONS_FLOW in
       uart_port.flags is avoided.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20260506121606.5805-3-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>