Please apply 32cba57ba74be to v4.1.y

Hi Sasha,

due to improved testing, I see crashes when running sabrelite images in qemu with v4.1.y and older kernels. Please apply 32cba57ba74be ("net: fec: introduce fec_ptp_stop and use in probe fail path") to v4.1.y to fix the problem in this release.

I'll send a backport to v3.18 separately.

Thanks, Guenter