Gfx-display: remove unnecessary sleep

Gfx-display: remove unnecessary sleep

BZ: 37477

5ms sleep is unnecessary in pr2 panel's IC initialization as panel reset can
make sure this wait time.

Change-Id: I735e9e00651b28885d59bbc24bf2d96f0441a908
Signed-off-by: Geng Xiujun <xiujun.geng@intel.com>
Reviewed-on: http://android.intel.com:8080/49804
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>
Reviewed-by: Hogander, Jouni <jouni.hogander@intel.com>
Tested-by: Tong, BoX <box.tong@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>