delivery mode and idle mode are x86 specific percpu, so move it from common to
x86 arch, also change the name of mode_to_idle to be idle_mode, change the name
of mode_to_kick_pcpu to be kick_pcpu_mode.
Tracked-On: #8812
Signed-off-by: Xue Bosheng <bosheng.xue@intel.com>
Acked-by: Wang, Yu1 <yu1.wang@intel.com>