* Backport:stm32f7: stm32_allocateheap: allow use DTCM memory for heap
Back port of upstrem contrib by Jussi Kivilinna <jussi.kivilinna@haltian.com>
stm32f7: stm32_allocateheap: allow use DTCM memory for heap
STM32F7 has up to 128KiB of DTCM memory that is currently left unused.
This patch adds DTCM to main heap if CONFIG_STM32F7_DTCMEXCLUDE is not enabled.
* px4fmu-v5_default:Enable inclusion of the DTCM in the heap
CONFIG_MM_REGIONS=3 adds the DTCM region to the heap.