d2: defconfig: Fix bcmdhd fw path

Upon concating revision for bcmdhd, the bcmdhd driver appends the
chip version to fw path. The current fw path can cause issues upon
enablement due to setting the firmware path to:

    /system/etc/wifi/bcmdhd_sta.bin_b2_b2

Change-Id: I664bd3e4594673c1fce91219d99df3821661274e
Signed-off-by: Luis Cruz <ljc2491@gmail.com>