drm/radeon/radeon_legacy_encoders: Move 'radeon_add_legacy_encoder's prototype to shared location

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/radeon/radeon_legacy_encoders.c:1746:1: warning: no previous prototype for ‘radeon_add_legacy_encoder’ [-Wmissing-prototypes]
 1746 | radeon_add_legacy_encoder(struct drm_device *dev, uint32_t encoder_enum, uint32_t supported_device)
 | ^~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Lee Jones <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

0 files changed, 0 insertions, 0 deletions