Make sure that PIPEDMCs are enabled whenever the corresponding pipe is
enabled.

This is required at least by the latest ADLP v2.18 firmware, which adds
a new handler enabled by default and running whenever the pipe is
enabled at the vertical referesh rate.

Bspec: 50344, 67620
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Tested-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102183324.862279-1-imre.deak@intel.com