usb: dwc3: msm: use of_platform API to create dwc3 core pdev

Currently platform_device_alloc() and platform_device_add() APIs
are being used to create dwc3 core pdev. Due to this, not able
to pass platform data from device tree to core pdev. Hence use
of_platform_populate() to create dwc3 core platform_device  from
device tree data.

Change-Id: Id731d759de65c8ae0f766b46bdeeec07afb6ad4b
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>