Add the stm32 debug bus driver that is responsible of checking the
debug subsystem accessibility before probing the related peripheral
drivers.
This driver is OP-TEE dependent and relies on the STM32 debug access
PTA.
Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Link: https://lore.kernel.org/r/20260226-debug_bus-v6-6-5d794697798d@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
