This patch set did some clean up and add runtime pm

Merge series from Haibo Chen <haibo.chen@nxp.com>:

PATCH1/3/4 to clean up the code, make the code more readable
PATCH2 add the runtime pm support
PATCH5 use devm_add_action_or_reset() to replace remove() callback, this can avoid
       oops when do bind/unbind test