drm/amd/pm: Sienna: Print failed BTC

Add a print in sienna_cichlid_run_btc() to help debug and to mirror other
platforms, as no print is present in the caller, smu_smc_hw_setup().

Cc: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>