drm/xe: Eliminate intel_fb_uses_dpt() call from __xe_pin_fb_vma()

drm/xe: Eliminate intel_fb_uses_dpt() call from __xe_pin_fb_vma()

Move the intel_fb_uses_dpt() out from __xe_pin_fb_vma() into
intel_plane_pin_fb() so that we don't do have display stuff
that deep in the pinning code.

And intel_fb_pin_to_ggtt() can just say "this does not need DPT"
always since it's specifically about pinning the fb into GGTT.
The previous logic here was kinda insane with the high level code
assuming GGTT, and low level code potentially deciding otherwise.
In practice it should have been fine because intel_fb_pin_to_ggtt()
only gets used from the initial_plane code, and there we are
not supposed to be have a framebuffer that needs DPT.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260416174448.28264-11-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>