drivers/net: use sleep delay by default for Intel NICs

drivers/net: use sleep delay by default for Intel NICs

NICs uses different delays up to a second during their
configuration. It makes no sense to busy-wait so long wasting
CPU cycles and preventing any other threads to execute on the
same CPU core. These busy polling are the rudiments that came
from the kernel drivers where you can not sleep in interrupt
context, but as we're in userspace, we're able and should
sleep to allow other threads to run.
Delays never called on rx/tx path, so this should not affect
performance.

Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>