kernel: Remove redundant TICKLESS_IDLE_SUPPORTED option

This flag is no longer necessary and TICKLESS_IDLE will be
enabled by default if SYS_POWER_MANAGEMENT is enabled.

Jira: ZEP-1325
Change-Id: Ic6cd4b8dc0a17c6a413cabf6509b215a4558318d
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
5 files changed