drm/msm/dp: remove the repeated declaration

Function 'dp_catalog_audio_enable' is declared twice, remove the
repeated declaration.

Cc: Rob Clark <[e-mail]>
Cc: Abhinav Kumar <[e-mail]>
Signed-off-by: Shaokun Zhang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Bjorn Andersson <[e-mail]>
Reviewed-by: Abhinav Kumar <[e-mail]>
Signed-off-by: Dmitry Baryshkov <[e-mail]>
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/dp/dp_catalog.h

···
 void dp_catalog_audio_set_header(struct dp_catalog *catalog);
 void dp_catalog_audio_config_acr(struct dp_catalog *catalog);
 void dp_catalog_audio_enable(struct dp_catalog *catalog);
-void dp_catalog_audio_enable(struct dp_catalog *catalog);
 void dp_catalog_audio_config_sdp(struct dp_catalog *catalog);
 void dp_catalog_audio_init(struct dp_catalog *catalog);
 void dp_catalog_audio_sfe_level(struct dp_catalog *catalog);