drm/i915/bw: Relocate intel_bw_crtc_min_cdclk()

drm/i915/bw: Relocate intel_bw_crtc_min_cdclk()

intel_bw_crtc_min_cdclk() (aka. the thing that deals with what bspec
calls "Maximum Pipe Read Bandwidth") doesn't really have anything to
do with the rest of intel_bw.c (which is all about SAGV/QGV and
memory bandwidth). Move it into intel_crtc.c (for the lack of a better
place).

And I don't really want to call intel_bw.c functions from intel_crtc.c,
so move out intel_bw_crtc_data_rate() as well. And when we move that we
pretty much have to move intel_bw_crtc_num_active_planes() as well since
the two are meant to be used as a pair (they both implement the same
"ignore the cursor" logic).

And in an effort to keep the namespaces at least semi-sensible we
flip the intel_bw_crtc_ prefix into intel_crtc_bw_.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20251013201236.30084-4-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>