drm/amdgpu/ucode: WARN() rather than BUG()

There's no need to crash the kernel for this case.

Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1478,7 +1478,8 @@ void amdgpu_ucode_ip_version_decode(struct amdgpu_device *adev, int block_type,
 		ip_name = "isp";
 		break;
 	default:
-		BUG();
+		WARN(1, "invalid HWIP %d\n", block_type);
+		return;
 	}
 
 	maj = IP_VERSION_MAJ(version);