1. Four-channel support
2. modified the public/pet_rfm_spu1/top/src/phy_init.s.c to sendto different apes
3. now case21 no use
4. Test:
4.1 spu_case0_arm_case0_cpri: Pass
4.2 spu_case14_arm_case20_cpri:Pass
4.3 spu_case20_arm_case20_cpri:Pass
4.4 spu_case24_arm_case24_cpri:Pass
4.5 spu_case34_arm_case5: Pass
4.6 spu_case44_arm_case5: Pass