usb: gadget: composite: enable BESL support

According to USB 2.0 ECN Errata for Link Power
Management (USB2-LPM-Errata-final.pdf), BESL
must be enabled if LPM is enabled.

This helps with USB30CV TD 9.21 LPM L1
Suspend Resume Test.

Change-Id: I3412d36959d0b6b49d369cb1695836af82d7b5b4
Signed-off-by: Felipe Balbi <balbi@ti.com>
Git-commit: a6615937
Git-repo:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git


Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>