amdgpu/dc: remove pointless returns in the i2caux constructor paths. (v2)

There was lots of return true, and error checking that was never used
in these paths.

Just remove it all.

v2: I missed one return true.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>