Kernel commit b6ae6fee73eab568ba49a4a489fdac6bb5027997 removed the
RTO-based flush logic in stm32-usart.
As a result, the RT patch no longer applies cleanly because it
modifies the receive_chars() call using the old context.
Update the RT patch to match the new baseline while preserving
the PREEMPT_RT locking changes.
https://onedigi.atlassian.net/browse/DEL-10000
Signed-off-by: Isaac Hermida <isaac.hermida@digi.com>
Sync STM32MP-specific RT kernel patches, aligned with the latest
ST release openstlinux-6.6-yocto-scarthgap-mpu-v25.06.11 from
meta-st-x-linux-rt layer.
Signed-off-by: Francisco Gil <francisco.gilmartinez@digi.com>
Isaac Hermida
Francisco Gil