usb: dwc3: core: Add error log when core soft reset failed

DWC3 controller soft reset is important operation for USB functionality.
In case when it fails, currently there is no failure log. Hence add
error log when core soft reset failed.

Signed-off-by: Mayank Rana <quic_mrana@quicinc.com>
Link: https://lore.kernel.org/r/1652897572-14461-1-git-send-email-quic_mrana@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>