USB: dwc3: msm: Fail probe if core-clk-rate is not passed from dts

Currently USB driver is not failing probe if USB core-clk-rate property
is not exist. This leads to USB enumeration failures across connect/
disconnect. Hence make core-clk-rate property mandatory and if in case
not defined, fail the probe. Also Fail probe if extcon property not
defined in case of OTG mode.

Also return error if dwc3_core_pre_init() fails during dwc3-msm_resume()
due to phy init fails and don't go ahead with setting up event buffers
as event buffers allocation is done.

Change-Id: I3927ad2f670e45acd10f8568857cf9f3434df657
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>