usb: dwc3: Do not set half-full elastic buffer

On some platforms setting of half-full elastic buffer will cause data
corruption and hence we need to avoid this setting.
Disable the usage of the default setting of half-full elastic buffer
towards SolvNet Case 8000626044.

Change-Id: I113c6e0602e057496d5e84fc2f6a3f59d12efc98
Signed-off-by: Maya Erez <merez@codeaurora.org>