there were 2 bugs
*) core1 came up with a bad bogo mips, looks like the clock needed time to stabilize
*) HPT frequency was not set making r4k timers not come up properly
Backport of 9551d91b1d "ralink: fix rcu_sched stalls on mt7621".
Signed-off-by: John Crispin <john@phrozen.org>