cpu-sched: Refactor common cpu affinity code

cpu-sched: Refactor common cpu affinity code

This patch includes
  - Refactoring of cpu-sched related code
    * 'cpu_sched_parse_cpuset' and 'cpu_shced_new_core' functions are moved
	  from cpu-sched.c to config-parser.c/h
    * Cpu common data structure (i.e., 'coreset' and 'core') is moved
	  from cpu-sched.c to cpu-common.h
    * Comments are modified
  - Renaming variable
    * Data structure: 'core' -> 'cpu_info' and 'coreset' -> 'cpuset_info'
    * Element: 'id' -> 'cpu_id' and 'on' -> 'online'
    * Other: minor change (such as local variable)

Change-Id: I1d04ee9c33b93f5f82504815c4344c2d472e25b8
Signed-off-by: Unsung Lee <unsung.lee@samsung.com>