cpu_hotpulg: Update timeout in utils.system() function call.

This function always fail for timeout in cpu_hotpulg virt test.
Set timeout to 60s.
kernelinstall: patch_list is supposed to be a list

And not a string to be broken down in a list. This follows what's
in the control file shipped with the test.

Signed-off-by: Cleber Rosa <crosa@redhat.com>