USB: dwc3-msm: Set speed as high speed if no speed information

Speed is not notified in case of platforms having micro USB connector
instead of USB type C connector. In this case, set speed as High speed
only as by default only high speed is supported over micro USB ports.

Change-Id: I6f29914ca9e2345157330651464b7a0c151f1f97
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>