drm/i915/tgl: Check the UC health of tc controllers after power on

New step added for TGL, required for us to check the TC
microcontroller health after power on TC aux.

BSpec: 49294

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190920205810.211048-7-jose.souza@intel.com