drm/radeon/evergreen: Remove the repeated declaration

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

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>