selftests: drivers: net: hw: Modify toeplitz.c to poll for packets

selftests: drivers: net: hw: Modify toeplitz.c to poll for packets

Prior to this the receiver would sleep for the configured timeout,
then attempt to receive as many packets as possible. This would result
in a large burst of packets, and we don't necessarily need that many samples.

The tests now run faster.

Before

 ok 12 toeplitz.test.rps_udp_ipv6
 # Totals: pass:12 fail:0 xfail:0 xpass:0 skip:0 error:0

 real	0m54.792s
 user	0m12.486s
 sys	0m10.887s

After

 ok 12 toeplitz.test.rps_udp_ipv6
 # Totals: pass:12 fail:0 xfail:0 xpass:0 skip:0 error:0

 real	0m36.892s
 user	0m4.203s
 sys	0m8.314s

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Dimitri Daskalakis <dimitri.daskalakis1@gmail.com>
Link: https://patch.msgid.link/20260207013018.551347-1-dimitri.daskalakis1@gmail.com
[pabeni@redhat.com: whitespaces fixes]
Signed-off-by: Paolo Abeni <pabeni@redhat.com>