clk: rockchip: add ROCKCHIP_PLL_SYNC_RATE flag to some plls

Add the new flag to gpll and cpll on rk3188 and similar and to
gpll, cpll and npll on rk3288.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Kever Yang <kever.yang@rock-chips.com>