Gfx-display: correct sleep time for pr2 panel reset

Gfx-display: correct sleep time for pr2 panel reset

BZ: 37475

This patch has following changes:
(1). change sleep time to 3ms between pulling panel reset pin low and high.
(2). change sleep time to 10ms after reset panel.
(3). using usleep_range rather than mdelay.

Change-Id: I2bd8960c10333d2e4e9b8fbcd46bc69d27587b4c
Signed-off-by: Geng Xiujun <xiujun.geng@intel.com>
Reviewed-on: http://android.intel.com:8080/49803
Reviewed-by: Xu, Randy <randy.xu@intel.com>
Reviewed-by: Hu, Austin <austin.hu@intel.com>
Reviewed-by: Zhang, Lei <lei.zhang@intel.com>
Reviewed-by: Ai, Ke <ke.ai@intel.com>
Tested-by: Tong, BoX <box.tong@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>