defconfig: QCS405: Enable USB diag_bridge, QRTR and RMNET host drivers

Enable USB diagfwd and diag_bridge drivers which are required to
communicate with connected diag device and diag forwarding to
host PC via USB. Also enable QRTR USB transport driver which
interfaces with QRTR framework to allow IPC between QCS405 and
connected device. Also enable USB host driver which probes a
connected RMNET interface on QCS405 and allows DATA message
exchange with device.

Change-Id: I0649bf59ff6e3d33f3820dbf5f2c3cb96705bb5d
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>