usb: dwc3: Add support for nominal elastic buffer

This patch adds support for nominal elastic buffer where elastic
buffer mode in GUSB3PIPE_CTRL(0) register will be cleared if
nominal elastic buffer is not present. This is done to avoid
high link error rates and superspeed mode transfer failures if
VDDCX is at super turbo mode voltage 1.05V.

Change-Id: Ifc21077c3009e025fb979132c7fd10b135bf69bb
Signed-off-by: Rohith Kollalsi <rkollals@codeaurora.org>