usb: dwc3-msm: Check host mode SuperSpeed on all ports

The controller is allowed to enter suspend when in host mode and
there are no active SuperSpeed connections. However, the check
currently assumes there is a single SS port whose PORTSC register
is at offset 0x430. This is incorrect if used on a controller
which has multiple root ports. Instead make sure to loop over
each of the PORTSC registers to check if any one of them are
enabled and in SuperSpeed.

Change-Id: Ib835d9efddaae3857e7c5ebd2b4336a963c61b78
Signed-off-by: Jack Pham <jackp@codeaurora.org>