defconfig: sdxprairie: Enable USB_BAM driver

USB BAM driver provides software interface to USB QDSS function
driver for programming USB BAM hardware using BAM driver APIs.
Hence enable USB_BAM driver on sdxprairie.

Change-Id: I6199e19f1f00160a1daf09a348307e990ce013a0
Signed-off-by: Mayank Rana <mrana@codeaurora.org>