Move write_lock from attrs to each attribute

Move write_lock from attrs to each attribute

Previously, a common write_lock is used for set_attribute and get_attribute of string type.
So, get_attribute function for string type should wait if some set_attribute function is working although it's not related each other.
This commit removes a common write lock and add each write_locks to attribute,
then lock dependencies are removed among each attributes.

[Version] 0.2.98
[Profile] Common
[Issue Type] Update
[Dependency module] N/A
[Test] [M(T) - Boot=(OK), sdb=(OK), Home=(OK), Touch=(OK), Version=tizen-3.0-mobile_20161122.5]

Change-Id: I3e11ace7200fd02ea4f05828b5ef5c116b15bbe5
Signed-off-by: Jeongmo Yang <jm80.yang@samsung.com>