cpuidle: intel_idle: Drop redundant backslash at line end

Drop a redundant backslash character at the end of a line in the
spr_cstates[] definition.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>