drm/amd/display: Change get_pipe_idx function scope

Turn previously global function into a static function as it is not used
outside the file.
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.c

@@ -251,7 +251,7 @@ unsigned int get_total_surface_size_in_mall_bytes(
 	return size;
 }
 
-unsigned int get_pipe_idx(struct display_mode_lib *mode_lib, unsigned int plane_idx)
+static unsigned int get_pipe_idx(struct display_mode_lib *mode_lib, unsigned int plane_idx)
 {
 	int pipe_idx = -1;
 	int i;

drivers/gpu/drm/amd/display/dc/dml/display_mode_vba.h

@@ -165,7 +165,6 @@ unsigned int get_total_surface_size_in_mall_bytes(
 		struct display_mode_lib *mode_lib,
 		const display_e2e_pipe_params_st *pipes,
 		unsigned int num_pipes);
-unsigned int get_pipe_idx(struct display_mode_lib *mode_lib, unsigned int plane_idx);
 
 bool get_is_phantom_pipe(struct display_mode_lib *mode_lib,
 		const display_e2e_pipe_params_st *pipes,