The CONFIG_FREERTOS_PLACE_FUNCTIONS_INTO_FLASH allows some FreeRTOS functions to be placed
into flash, thus saving some IRAM. However, this feature was previously not supported for
SMP FreeRTOS.
This commit adds CONFIG_FREERTOS_PLACE_FUNCTIONS_INTO_FLASH support for SMP FreeRTOS. There
are now separate linker fragment files for IDF FreeRTOS and SMP FreeRTOS, named "linker.lf"
and "linker_smp.lf" respectively.
