drm/amdgpu: fix initial connector audio value

[ Upstream commit 4bb71fce58f30df3f251118291d6b0187ce531e6 ]

This got lost somewhere along the way, This fixes
audio not working until set_property was called.

Signed-off-by: hongao <hongao@uniontech.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>