drm/i915/alpm: ALPM disable fixes

drm/i915/alpm: ALPM disable fixes

PORT_ALPM_CTL is supposed to be written only before link training. Remove
writing it from ALPM disable.

Also clearing ALPM_CTL_ALPM_AUX_LESS_ENABLE and is not about disabling ALPM
but switching to AUX-Wake ALPM. Stop touching this bit on ALPM disable.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/7153
Fixes: 1ccbf135862b ("drm/i915/psr: Enable ALPM on source side for eDP Panel replay")
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: <stable@vger.kernel.org> # v6.10+
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Link: https://patch.msgid.link/20260212062731.397801-1-jouni.hogander@intel.com