usb: gadget: composite: Inform controller driver of self-powered

Different configuration/condition may draw different power. Inform the
controller driver of the change so it can respond properly (e.g.
GET_STATUS request). This fixes an issue with setting MaxPower from
configfs. The composite driver doesn't check this value when setting
self-powered.

Cc: stable@vger.kernel.org
Fixes: 88af8bbe ("usb: gadget: the start of the configfs interface")
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Git-commit: 5e5caf4fa8d3039140b4548b6ab23dd17fce9b2c
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Change-Id: I96588f97d32c9b6d80302e601cb0cc8d771c1296
Signed-off-by: Mayank Rana <mrana@codeaurora.org>