Porting Miosix to stm32h7 -- first part

miosix/_tools/testsuite/testsuite.cpp

miosix/arch/common/core/interrupts.h

miosix/arch/common/core/memory_protection.h

miosix/arch/common/drivers/serial.h

miosix/arch/common/drivers/serial_stm32.cpp

miosix/arch/common/drivers/serial_stm32.h

miosix/config/Makefile.inc

miosix/interfaces/atomic_ops.h

miosix/interfaces/endianness.h