drm/amd/display: Remove duplicated include in dcn35_hwseq.c

./drivers/gpu/drm/amd/display/dc/dcn35/dcn35_hwseq.c: clk_mgr.h is included more than once.
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn35/dcn35_hwseq.c

@@ -31,7 +31,6 @@
 #include "clk_mgr.h"
 #include "reg_helper.h"
 #include "abm.h"
-#include "clk_mgr.h"
 #include "hubp.h"
 #include "dchubbub.h"
 #include "timing_generator.h"