drm/i915/dsb: Shuffle code around

drm/i915/dsb: Shuffle code around

Relocate intel_dsb_dewake_scanline() and dsb_chicken() upwards
in the file. I need to reuse these while emitting DSB
commands, and I'd like to keep the DSB command emission
stuff more or less grouped together in the file.

Also drop the intel_ prefix from intel_dsb_dewake_scanline() since
it's all internal stuff and thus doesn't need so much namespacing.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240624191032.27333-6-ville.syrjala@linux.intel.com
Reviewed-by: Animesh manna <animesh.manna@intel.com>