msm_fb: display: Configure solidfill color to black

The solidfill color was getting reset to to default state to white.
Correctly reseting to black by default.

Crs-Fixed: 453600
Change-Id: I203ce61867d009509bf6acd01169f1fb0b223652
Signed-off-by: Siddhartha Agrawal <agrawals@codeaurora.org>