Revert "usb: dwc3: gadget: extract dwc3_gadget_ep_skip_trbs()"

This reverts commit 65e1f340.

This is a preparation change for merging android-4.19.57 into
msm-4.19 branch.

Reverted due to BootTimeRunner regression.

Change-Id: I27d5703307f29d28799695f4d630149cc7ab8e73
Signed-off-by: Ivaylo Georgiev <irgeorgiev@codeaurora.org>