msm: qdspv6: fix ultrasound file organization

Versions A and B were placed in separate directories but have two
sources files in common and only one difference.  The Makefiles were
setup to skip the intermediate version directory, which caused
unnecessary relative includes.  Simplify the organization by putting
evenything in one directory.

Signed-off-by: Bryan Huntsman <bryanh@codeaurora.org>