A board can now define MBOOT_LD_FILES (at the Makefile-level) to specify
custom linker scripts. And stm32_generic.ld has been split into 2 pieces
so one or the other can be reused (usually stm32_sections.ld wolud be
reused by a board, and stm32_memory.ld redefined).
Signed-off-by: Damien George <damien@micropython.org>
Damien George