clk: imx: clk-divider-gate: drop redundant initialization

There is no need to initialize flags as 0.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>