reboot on wandboard fails with v4.14.67 (bisected to 2059e527a6)

From: Rasmus Villemoes
Date: Wed Aug 29 2018 - 05:56:09 EST

We're using imx_v6_v7_defconfig on our Wandboards. After upgrading to
v4.14.67, reboot no longer works (or, well, takes a very long time when
the watchdog is configured).

v4.14.66 works fine, the breakage bisects to
2059e527a659cf16d6bb709f1c8509f7a7623fc4 (ARM: imx_v6_v7_defconfig:
Select ULPI support), and reverting that on top of v4.14.67 again works.