lpm-levels: Use arm_cpuidle_suspend instead of cpu_suspend

Use of cpu_suspend is deprecated. Instead use arm_cpuidle_suspend for
32bit systems.

Change-Id: I5c61c970e17cba44c555e60418a9ece80c61488f
Signed-off-by: Raju P.L.S.S.S.N <rplsssn@codeaurora.org>