disp: msm: dsi: remove using static memory for roi commands

Partial update commands are using static memory. For dual dsi,
both dsi's can manipulate on same memory, if partial update is enabled
on both of them. Change removes the static configuration.

Change-Id: I0ca16324a27427d13deaa9d18e3ab4f47fe1cc21
Signed-off-by: Vara Reddy <varar@codeaurora.org>