clk: rockchip: rk356x: Add CLK_USB3OTGx_REF support

The CLK_USB3OTGx_REF clocks is used as reference clock for USB3 block.

Add simple support to get rate of CLK_USB3OTGx_REF clocks to fix
reference clock period configuration.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Acked-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
1 file changed