Define according the used Cortex core ARM_MATH_CM7, ARM_MATH_CM4, ARM_MATH_CM3, ARM_MA

ARM_MATH_CM7, ARM_MATH_CM4, ARM_MATH_CM3, ARM_MATH_CM0, and ARM_MATH_CM0+_are different Cortex-M processor cores from ARM, and the suffixes denote the specific core that the math library is optimized for.

ARM_MATH_CM7 is optimized for Cortex-M7 processors, which are high-performance microcontrollers with advanced features like a dual-issue pipeline, a floating-point unit, and a DSP instruction set.

ARM_MATH_CM4 is optimized for Cortex-M4 processors, which are similar to Cortex-M7 processors but with slightly lower performance and fewer features.

ARM_MATH_CM3 is optimized for Cortex-M3 processors, which are lower-performance microcontrollers that lack floating-point hardware.

ARM_MATH_CM0 is optimized for Cortex-M0 processors, which are even lower-performance microcontrollers that are designed for cost-sensitive applications.

ARM_MATH_CM0+ is optimized for Cortex-M0+ processors, which are similar to Cortex-M0 processors but with added features like a single-cycle multiply instruction.