kernel-test-nohz: Add postinst/postrm script fragments for configuring CPU isolation
kernel-test-nohz: Add postinst/postrm script fragments for configuring CPU isolation

The NO_HZ_FULL kernel ptest relies on CPU isolation for running an
undisturbed RT polling test.

Add a postinst script fragment that changes the kernel boot parameters via
the 'othbootargs' variable to include the necessary 'isolcpus' and
'nohz_full' parameters configured to use the last CPU available on the
system under test. These parameters isolate that CPU and flag it for
stopping the scheduler tick whenever possible.

The corresponding postrm script fragment undoes changes to 'othbootargs'.

Signed-off-by: Gratian Crisan <17cf39b7426cfdea7dd491f7105a23841aaa302f@ni.com>

ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt