net/ena/base: make delay exponential in polling functions

net/ena/base: make delay exponential in polling functions

Instead of the fixes, 5 ms delay in the polling functions, use
values into given range (by default from 100 us 5000 us) and increase
them exponentially each time, the operation isn't finished.

This change can improve responsiveness of the driver for the fast
operations.

Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>