Revert "usb: dwc3: gadget: Fix OTG events when gadget driver isn't loaded"

This reverts commit 1e55e3f6.

This is a preparation change for merging android-4.19.34 into
msm-4.19 branch.

This change was introduced for SNPS core configured for OTG 2.0 only, which
does not hold true for qcom socs. It leads to unclocked register access.

Change-Id: I039fae6ca5b6f561f99f73bb892c68cb62c7a7df
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Ivaylo Georgiev <irgeorgiev@codeaurora.org>