drm/i915: Preallocate the debug power domain wakerefs array

Since the current size of intel_display_power_domain_set struct is
close to 1kB, it's better to use preallocated memory for it. The only
user of the intel_display_power_get/put_in_set() allocating the struct
on stack is hsw_get_pipe_config(), so we can avoid potential stack
overallocations by moving the struct here to the preallocated
intel_crtc struct (hsw_get_pipe_config() is non-reentrant wrt. each
CRTC).

This patch replaces
https://lore.kernel.org/intel-gfx/20221107170917.3566758-5-imre.deak@intel.com/T/#md3f6cdf17fcd



Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221114122251.21327-3-imre.deak@intel.com