Haven't been able to boot agd5f kernels for a while, did a big bisect today.
It came up with this commit:

commit 6f0359ff73076483902de0c17f9649bf55651e2a
Author: Alex Deucher <alexander.deucher@amd.com>
Date:   Wed Aug 24 17:15:33 2016 -0400

    drm/amdgpu/vce3: add support for third vce ring

    Not of much use at the moment (we don't really use
    the second ring either), but may be useful later.

    Reviewed-by: JimQu <Jim.Qu@amd.com>
    Reviewed-by: Christian König <christian.koenig@amd.com>
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

[    16.822] (--) AMDGPU(0): Chipset: "FIJI" (ChipID = 0x7300)