clk: rockchip: rk3036: fix the FLAGs for clock mux

The DFLAGS are used for the clock dividers, the CLKSEL_CON flags
of COMPOSITE_NODIV type should be MFLAGS.

Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>