mdss: display: do not enable dsi irq from dsi host init

Dsi irq is enabled at beginning of transaction and disabled at
end of transaction. There is no need to enable dsi irq at
initialization time.

Change-Id: Ie4ffbbae6e3d8234714a51555ec95ce3678862cc
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>