arch: arm: update compile options for DSP

This commit updates the compile options in cmake to distinguish
between ARMv8-M Mainline MCUs with or withouth the optional DSP
extension. A new Kconfig option: ARMV8_M_DSP, is introduced, to
signify the use of an ARMv8-M MCU with DSP support.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
3 files changed