dpdk: replace TSC clock with GetTime (gettimeofday) function

dpdk: replace TSC clock with GetTime (gettimeofday) function

Getting clock through Time Stamp Counter (TSC) can be precise and fast,
however only for a short duration of time.
The implementation across CPUs seems to vary. The original idea is to
increment the counter with every tick. Then dividing the delta of CPU ticks
by the CPU frequency can return the time that passed.
However, the CPU clock/frequency can change over time, resulting in uneven
incrementation of TSC. On some CPUs this is handled by extra logic.
As a result, obtaining time through this method might drift from the real
time.

This commit therefore substitues TSC time retrieval by the standard system
call wrapped in GetTime function - on Linux it is gettimeofday.

Ticket: 7115