drm/i915/skl: Introduce intel_num_planes()
drm/i915/skl: Introduce intel_num_planes()

It can be handy to get the number of planes for this pipe, ie including
the primary plane to loop over them. Introduce a little function to do
so.

Reviewed-by: Rodrigo Vivi <f714145d6ee82178e54021e0c168f56d17b53c9c@intel.com>
Signed-off-by: Damien Lespiau <64bd3cb94f359c1a3ce68dae5e26b40578526277@intel.com>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs