msm: mdss: hdmi: cleanup wakeup calls

Do not lock in wakeup functions as it may block current thread.
Wakeup can trigger a callback looking to acquire same lock.
Also rename the wakeup command names to properly identify client
and lib commands.

Change-Id: I28411714d2d7f0104364726fc5ce0593e5ccff91
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>