drm/i915: Group all the PPS init steps to one place

drm/i915: Group all the PPS init steps to one place

Move the early PPS initialization calls next to the rest of PPS
initialization steps. This allows us to forgo a duplicated call to
intel_dp_init_panel_power_sequencer_registers() on VLV/CHV.

This will swap the order of DP AUX registration wrt. PPS initialization.
There is an existing race here in case of a user space access via the
DPAUX device node after DP AUX registration and before calling
intel_dp_init_panel_power_sequencer_registers(), but this change won't
make this worse. The fix for this is to separate DP AUX initialization
and registration, that's a separate work already underway.

The order of MST wrt. PPS init as well as the order of
intel_dp_init_panel_power_sequencer_registers() wrt.
intel_edp_panel_vdd_sanitize() also swap, which is ok, there are no
dependencies between these steps.

Suggested by Ville.

CC: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466499109-20240-4-git-send-email-imre.deak@intel.com