clk: rockchip: fix hclk_vio_niu on rk3328

The clock wrongly was called hclk_vio and exported, while it actually is
a clock of the interconnect-vio connection and should therefore be always
on till we actually model the interconnect.

So fix that and don't export it as HCLK_VIO.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>