drm/stm: dsi: check hardware version

Check version of DSI hardware IP. Only versions 1.30 & 1.31
are supported.

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
Acked-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1557500579-19720-1-git-send-email-yannick.fertre@st.com