This patch moves amdgpu_fbdev_set_suspend() to the beginning
of suspend sequence.

This is to ensure fbcon does not to write to the VRAM
after GPU is powerd down.
Signed-off-by: NShirish S <shirish.s@amd.com>
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>