usb: dwc3: debugfs: Add support for 64bit division on 32bit chipsets

This change adds support for 64bit division on 32bit LE targets
using do_div() api.

Change-Id: I30247f514e13bcba80f707acccd65878de38dff5
Signed-off-by: Elson Roy Serrao <eserrao@codeaurora.org>