msm8994: ultrasound: enable ultrasound support for msm8994

Add ultrasound compilation flag and small fix to
struct used in compat mode

Change-Id: I0f0f4f841f034159d81e7498db22fff76f975d49
Acked-by: Hadar Sivan <hsivan@qti.qualcomm.com>
Signed-off-by: Lior Barenboim <liorb@codeaurora.org>