display: lock: Remove del_state_cond()

display: lock: Remove del_state_cond()

In the plugins/display/core.c, del_state_cond/del_(normal/dim/off)_cond() was copied to all plugins.
Actually, there is no need to create a function remove cond for each state.
And, del_state_cond() is used to delete the registered pmlock.

These are changes in this patch related to delete cond_head.
1. Remove del_state_cond() which was used as timeout callback funtion.
2. Remove update_lock_timer() which is not necessary.
3. del_state_cond() routine is added to add_node().
4. Change add_node() to
PmLockNode *display_lock_add_pmlock_node(enum state_t s_index, pid_t pid, bool holdkey_block, unsigned int timeout);

Actually, add_callback function not needs pid, state params.
Because PmLockNode already has that pid, state information and callback is added when the PmLockNode is created.
Thus, add callback and pmlock_node handling routine is moved to display-lock.

For reference assert statement, callback function is added under the conditions.
1. When the pmlock is created
2. When the existing pmlock is updated.
Exisiting callback function is removed when the pmlock is updated or removed.

Change-Id: Iace657049934e531a876be971dc42e6114620f7d
Signed-off-by: Yunhee Seo <yuni.seo@samsung.com>