drm/mediatek: mtk_dsi: Remove unnecessary print function dev_err()

The print function dev_err() is redundant because platform_get_irq()
already prints an error.

Eliminate the follow coccicheck warning:
./drivers/gpu/drm/mediatek/mtk_dsi.c:1092:2-9: line 1092 is redundant
because platform_get_irq() already prints an error

Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220224012318.84935-1-yang.lee@linux.alibaba.com/


Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>