drm/i915: Add helper to modeset a set of pipes

drm/i915: Add helper to modeset a set of pipes

Add intel_modeset_pipes_in_mask_early() to modeset a provided set of
pipes, used in a follow-up patch.

As opposed to intel_modeset_all_pipes() which modesets only the active
pipes - others don't requiring programming the HW - modeset all enabled
pipes in intel_modeset_pipes_in_mask_early() which may need to recompute
their state even if they are not active (that is in the DPMS off state).

While at it add DocBook descriptions for the two exported functions.

v2:
- Add a flag controlling if active planes are force updated as well.
- Add DockBook descriptions.
v3:
- For clarity use _early/_late suffixes for the exported functions
  instead of the update_active_planes parameter. (Ville)
v4:
- In intel_modeset_pipes_in_mask_early() update only the crtc
  flags relevant to the early phase. (Ville)
- Rename intel_modeset_all_pipes() in a separate patch.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230921195159.2646027-7-imre.deak@intel.com