validation: scheduler: increase delay tolerance
validation: scheduler: increase delay tolerance

For some systems sensitive to time deviation, would be better
to have some time backup while testing scheduler time, so increase
it to 3 jiffies.

https://bugs.linaro.org/show_bug.cgi?id=2076

Signed-off-by: Ivan Khoronzhuk <15ad2a232c436ab54d1b78ef06a09c4cd03911f0@linaro.org>
Reviewed-by: Bill Fischofer <52f3c909d51cc5d355a68a403df6906b3c1a8f83@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

nmorey/odp,nmorey/odp,nmorey/odp,erachmi/odp,dkrot/odp,mike-holmes-linaro/odp,ravineet-singh/odp,erachmi/odp,mike-holmes-linaro/odp,mike-holmes-linaro/odp,ravineet-singh/odp,dkrot/odp,nmorey/odp,ravineet-singh/odp,ravineet-singh/odp,erachmi/odp,mike-holmes-linaro/odp,erachmi/odp,dkrot/odp,dkrot/odp