drm/amd/amdgpu: add dummy_page_addr to sriov msg

Add dummy_page_addr to sriov msg for host driver to set
GCVM_L2_PROTECTION_DEFAULT_ADDR* registers correctly.

v2:
should update vf2pf msg instead

Signed-off-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Reviewed-by: Horace Chen <horace.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>