selftests: bonding: Increase timeout to 1200s

When tests are run by runner.sh, bond_options.sh gets killed before
it can complete:

make -C tools/testing/selftests run_tests TARGETS="drivers/net/bonding"
	[...]
	# timeout set to 120
	# selftests: drivers/net/bonding: bond_options.sh
	# TEST: prio (active-backup miimon primary_reselect 0)                [ OK ]
	# TEST: prio (active-backup miimon primary_reselect 1)                [ OK ]
	# TEST: prio (active-backup miimon primary_reselect 2)                [ OK ]
	# TEST: prio (active-backup arp_ip_target primary_reselect 0)         [ OK ]
	# TEST: prio (active-backup arp_ip_target primary_reselect 1)         [ OK ]
	# TEST: prio (active-backup arp_ip_target primary_reselect 2)         [ OK ]
	#
	not ok 7 selftests: drivers/net/bonding: bond_options.sh # TIMEOUT 120 seconds

This test includes many sleep statements, at least some of which are
related to timers in the operation of the bonding driver itself. Increase
the test timeout to allow the test to complete.

I ran the test in slightly different VMs (including one without HW
virtualization support) and got runtimes of 13m39.760s, 13m31.238s, and
13m2.956s. Use a ~1.5x "safety factor" and set the timeout to 1200s.

Fixes: 42a8d4aa ("selftests: bonding: add bonding prio option test")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20240116104402.1203850a@kernel.org/#tSuggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240118001233.304759-1-bpoirier@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/drivers/net/bonding/settings

-timeout=120
+timeout=1200