Description: serial: imx: fix tx statemachine deadlock
References:
Notes:
 carnil> Commit fixes cb1a60923609 ("serial: imx: implement rts delaying
 carnil> for rs485") in 5.9-rc1.
Bugs:
upstream: released (6.8-rc1) [78d60dae9a0c9f09aa3d6477c94047df2fe6f7b0]
6.7-upstream-stable: released (6.7.2) [9a662d06c22ddfa371958c2071dc350436be802b]
6.6-upstream-stable: released (6.6.14) [763cd68746317b5d746dc2649a3295c1efb41181]
6.1-upstream-stable: released (6.1.75) [63ee7be01a3f7d28b1ea8b8d7944f12bb7b0ed06]
5.10-upstream-stable: released (5.10.209) [6e04a9d30509fb53ba6df5d655ed61d607a7cfda]
4.19-upstream-stable: N/A "Vulnerable code not present"
sid: released (6.6.15-1)
6.1-bookworm-security: released (6.1.76-1)
5.10-bullseye-security: released (5.10.209-1)
4.19-buster-security: N/A "Vulnerable code not present"