introduce global DSP_SHARING and CPU_HAS_DSP to be used by all
architectures and change existing usage in ARC to use those global
configs.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
add DSP reg in context switch
add AGU reg in context switch to support XY mem
add thread option and API to dis/enable DSP switch
Signed-off-by: Siyuan Cheng <siyuanc@synopsys.com>