drm/i915/cnl+: Verify combo PHY HW state during PHY uninit

Verify on CNL, ICL that the combo PHY HW state stayed intact after PHY
initialization.

v2:
- Print 'Port X' as we do elsewhere instead of 'Port-X'. (Jose)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181106160621.23057-4-imre.deak@intel.com