linux-gen: time: improve x86 TSC freq measurement accuracy
linux-gen: time: improve x86 TSC freq measurement accuracy

Add short warm up round and measure over a longer period of
time (250ms vs 100ms).

Signed-off-by: Petri Savolainen <d528fd253b9aaf78fa72edbcc6249e82047f6ce6@linaro.org>
Reviewed-and-tested-by: Bill Fischofer <52f3c909d51cc5d355a68a403df6906b3c1a8f83@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

dkrot/odp,dkrot/odp,dkrot/odp,dkrot/odp