Revert "drm/i915: Disable DC states for all commits"

Revert "drm/i915: Disable DC states for all commits"

This reverts commit 0fc6fea41c7122aa5f2088117f50144b507e13d7 which is
commit a2b6e99d8a623544f3bdccd28ee35b9c1b00daa5 upstream.

It is reported to cause regression issues, so it should be reverted from
the 6.1.y tree for now.

Reported-by: Thorsten Leemhuis <regressions@leemhuis.info>
Link: https://lore.kernel.org/r/f0870e8f-0c66-57fd-f95d-18d014a11939@leemhuis.info
Link: https://gitlab.freedesktop.org/drm/intel/-/issues/8419
Cc: Manasi Navare <navaremanasi@google.com>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Jouni Högander <jouni.hogander@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>