[lvc-project] [PATCH 5.19 0/2] tty: n_gsm: revert tx_mutex usage

[Fedor Pchelkin]

Thanks for notice, n_gsm tx_mutex patches just were added to 5.19, not
5.15, so we need to revert them.

I'm sorry for the inconvenience with 5.10 revert patch, fixed that in
the corresponding thread.