dt-bindings: import headers for MSM8996

Import dt-binding headers for MSM8996/APQ8096 from Linux.

Taken from kernel tag v6.7

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>