usb: dwc3: restart usb upon endpoint cmd timeout

Sometime endpoint command timeout happening after
usb device enumeration. Controller stops responding to
any endpoint commands afterwards. To recover from this
condition restart usb by simulating vbus off and on
except for end transfer command. Also increase the
command timeout from 1500us to 3000us.

Change-Id: I7c1833d844fd432b33158686361e24e66a2fd92c
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>