drm/amdgpu: fix duplicated value setting in dce100_resource_construct()

i2c_speed_in_khz was set twice with the same values. Looking at other DCE
versions, we probably wanted to set the value for i2c_speed_in_khz_hdcp.

Signed-off-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>