Modernized include guards in arch_settings.h

miosix/arch/arm7_lpc2000/common/arch_settings.h

miosix/arch/cortexM0_stm32/common/arch_settings.h

miosix/arch/cortexM3_efm32gg/common/arch_settings.h

miosix/arch/cortexM3_stm32/common/arch_settings.h

miosix/arch/cortexM3_stm32f2/common/arch_settings.h

miosix/arch/cortexM3_stm32l1/common/arch_settings.h

miosix/arch/cortexM4_stm32f3/common/arch_settings.h

miosix/arch/cortexM4_stm32f4/common/arch_settings.h

miosix/arch/cortexM4_stm32l4/common/arch_settings.h

miosix/arch/cortexM7_stm32f7/common/arch_settings.h

miosix/arch/cortexM7_stm32h7/common/arch_settings.h