arm/dts: Enable workaround for superspeed enumeration issue for msm8974

Commit ba9d3bf3: "USB: dwc3: Add support
for fixing superspeed enumeration issue" added workaround in dwc3-msm
driver for fixing superspeed enumeration issue. Hence enable the quirk
for this workaround to be enabled on msm8974 for fixing the same.

CRs-Fixed: 637902
Change-Id: I5c94d602e0015d85adeee89112a3c82b1b277759
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>