quark_se_ss: power_mgmt: Remove redundant int trigger setting

Zephyr is always setting irqs to be level triggered as
required by the core. It is unnecessary to set it to
level again while entering sleep states.

Change-Id: I10f919d619af2e1ab05dc85a67766929b6ae9402
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>