tests: drivers: dma: chen_blen_transfer: add bdma test to nucleo_h743zi

Add unit tests for BDMA driver.

Also requires adding additional kconfig options to allocate
the memory buffers in a specific SRAM section, because
the BDMA only has access to SRAM4.

Signed-off-by: Hein Wessels <heinwessels93@gmail.com>