[CPUFREQ] S5PV210: Add additional symantics for "relation" in cpufreq with pm

Relation has an additional symantics other than standard.
s5pv310_target funtion have below additional relation.
- DISABLE_FURTHER_CPUFREQ : disable further access to target
- ENABLE_FURTHER_CPUFRER : enable access to target

Signed-off-by: Huisung Kang <hs1218.kang@samsung.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>