stm32: dmamux: change initialization order to PRE_KERNEL_1

When running the tests of the async api of uart
on nucleo-l4r5zi we get MPU fault.
The reason is ordering initialization. The uart and dma
drivers are initialized PRE_KERNEL_1 while dmamux is
initialized POST_KERNEL.
Thus, the function device_get_binding fails since the
dmamux device is not ready to be used.

Fixes: #32715.

Signed-off-by: Shlomi Vaknin <[email protected]>

drivers/dma/dmamux_stm32.c

@@ -252,7 +252,7 @@ DEVICE_DT_INST_DEFINE(index, \
  &dmamux_stm32_init, \
  device_pm_control_nop, \
  &dmamux_stm32_data_##index, &dmamux_stm32_config_##index,\
- POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, \
+ PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, \
  &dma_funcs);
 
 DT_INST_FOREACH_STATUS_OKAY(DMAMUX_INIT)