MAINTAINERS: usb: add entry for isp1760

Giving support for isp1763 made a little revival to this driver, add
entry in the MAINTAINERS file with me as maintainer.

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Link: https://lore.kernel.org/r/20210607170054.220975-1-rui.silva@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>