drm/amdgpu: fix DRM_INFO flood if display core is not supported (bug 210921)

This fix bug 210921 where DRM_INFO floods log when hitting an unsupported ASIC in
amdgpu_device_asic_has_dc_support(). This info should be only called once.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=210921Signed-off-by: NAlexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -3034,7 +3034,7 @@ bool amdgpu_device_asic_has_dc_support(enum amd_asic_type asic_type)
 #endif
 	default:
 		if (amdgpu_dc > 0)
-			DRM_INFO("Display Core has been requested via kernel parameter "
+			DRM_INFO_ONCE("Display Core has been requested via kernel parameter "
 					 "but isn't supported by ASIC, ignoring\n");
 		return false;
 	}