pass: resmon: Move private pass_resmon structure for encapsulation

pass: resmon: Move private pass_resmon structure for encapsulation

The struct pass_resmon is private data structure and the other module
cannot access the data of struct pass_resmon directly. In order to
protect the data, move private pass_resmon structure into pass_resmon
module and then provide the proper getter/setter function to handle the
data.

Change-Id: Ic4d1d8d0d11294e173ba19cc08b50a459a878492
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>