usb_get_controller_id() API shall returns non-negative number as valid id
related to USB controller if alias is found. Current code considers zero
as only valid controller id and doesn't update for secondary USB controller
(i.e. id as 1). This results into passing controller id as zero instead of
1 causing bus error when ADSP USB driver is trying to access primary USB
controller's register (it is supposed to access USB secondary controller's
register) when primary USB controller related clocks are voted off. Fix
this issue by updating check to consider all non-negative number as valid
number and updating same.
Change-Id: Id15edbdfd6c924000da18bbb82d0483d4d110d41
Signed-off-by: Mayank Rana <mrana@codeaurora.org>