This reverts commit 7190401f.

Verifying the clock source sometimes deems the MIPS clock
to be unstable, at least in qemu.

clocksource: timekeeping watchdog on CPU0: Marking clocksource 'MIPS' as unstable because the skew is too large:
clocksource:                       'jiffies' wd_nsec: 500000000 wd_now: ffff8bde wd_last: ffff8bac mask: ffffffff
clocksource:                       'MIPS' cs_nsec: 940634468 cs_now: 310181c4 cs_last: 28090a09 mask: ffffffff
clocksource:                       Clocksource 'MIPS' skewed 440634468 ns (440 ms) over watchdog 'jiffies' interval of 500000000 ns (500 ms)
clocksource:                       'MIPS' is current clocksource.

If this happens, network interfaces fail to come online.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>