msm: mdss: cleanup OPPO's panel reset code part three

* PS1 : Find7s
* PS2 : Find7a
        Restore gpio_request_done handling
* PS3 : Remove gpio_request_done code
        Restore checking for panel_power_on,
        which is passed from dsi_v2 driver

Change-Id: I1cdc405c60a7e5b6536d027fa5f925a7e70c5c84