msm: camera: csiphy: Reset phy config count in phy release

If there are multiple phy streamOn, streamOff happening
in a session with the phy re-configured at each streamOn,
the phy config count won't be reset properly at release. As
a result, the phy config params won't be reset either and
will persist till the next session/acquire.

This change resets the config count if the acquire count
has already been reset i.e. all devices have been released.

Change-Id: I774e9ce60cedb5e6ebbdc51f923e60630e30fcd4
Signed-off-by: Shankar Ravi <rshankar@codeaurora.org>