intel_idle: Add Meteorlake support

Add intel_idle support for MeteorLake.

C1 and C1E states on Meteorlake are mutually exclusive, like Alderlake
and Raptorlake, but they have little latency difference with measureable
power difference, so always enable "C1E promotion" bit and expose C1E
only.

Expose C6 because it has less power compared with C1E, and smaller
latency compared with C8/C10.

Ignore C8 and expose C10, because C8 does not show latency advantage
compared with C10.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>