msm: mdss: add support to program of HSTX drivers for DSI 12nm PHY

Add support to program HSTX drivers in DSI 12nm PHY which is
needed for HS data transfer.

Change-Id: If3823f5a425f6d1c7781bd5d62d16d097f3b8ca0
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>