tests: kernel: import irq_offload test from legacy

This test was not using any legacy APIs, so simply
removed legacy from conf and ini's.

Jira: ZEP-932

Change-Id: I5a4b475ac5056b6d6aa64baef6bda53f20d8548e
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
8 files changed