mmhub_v1_0_get_clockgating missing return on SR-IOV VF path reads host-managed registers

Summary

mmhub_v1_0_get_clockgating L552-553 if(amdgpu_sriov_vf(adev))*flags=0; no return after. Sibling mmhub_v1_0_set_clockgating L524-525 correctly if(amdgpu_sriov_vf(adev))return 0; Getter falls through L556-563 RREG32_SOC15(ATHUB,0,mmATHUB_MISC_CNTL) and RREG32_SOC15(MMHUB,0,mmATC_L2_MISC_CG) on VF and ORs bits into *flags defeating intended VF bypass. Impact bounded: SR-IOV VF MMIO to host-owned MMHUB/ATHUB registers trapped/emulated by host PF no host kernel memory leak; only consumer in-kernel CG state machine. Worst: incorrect CG state on VF itself self-DoS of guest GPU not cross-tenant/privilege/memory. Defense-in-depth. Fix: add return after *flags=0 for VF mirroring set_clockgating.