drm/amd/powerplay: remove duplicate include

Remove asic_reg/nbio/nbio_6_1_offset.h which is included more than once
Reviewed-by: NEvan Quan <evan.quan@amd.com>
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NWang Hai <wanghai38@huawei.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega12_inc.h

@@ -34,7 +34,6 @@
 #include "asic_reg/gc/gc_9_2_1_offset.h"
 #include "asic_reg/gc/gc_9_2_1_sh_mask.h"
 
-#include "asic_reg/nbio/nbio_6_1_offset.h"
 #include "asic_reg/nbio/nbio_6_1_offset.h"
 #include "asic_reg/nbio/nbio_6_1_sh_mask.h"