clk: imx: clk-imx6q: Let OSC to be routed to anaclk2/2b

OSC can be used as USB hub source clock. An example we can route to
CLK2_P imx6 pin.

This show a usage example:

[...]
	usb_hub: usb-hub {
		compatible = "smsc,usb3503a";
		clocks = <&clks IMX6QDL_CLK_LVDS2_GATE>;
		clock-names = "refclk";
	};
};

[...]
&clks {
        assigned-clocks = <&clks IMX6QDL_CLK_LVDS2_SEL>;
        assigned-clock-parents = <&clks IMX6QDL_CLK_OSC>;
};

/sys/kernel/debug/clk/clk_summary

osc                                 5            5    24000000          0 0
[...]
    lvds2_sel                       1            1    24000000          0 0
       lvds2_gate                   1            1    24000000          0 0
[...]
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk-imx6q.c

@@ -70,7 +70,8 @@ static const char *cko_sels[] = { "cko1", "cko2", };
 static const char *lvds_sels[] = {
 	"dummy", "dummy", "dummy", "dummy", "dummy", "dummy",
 	"pll4_audio", "pll5_video", "pll8_mlb", "enet_ref",
-	"pcie_ref_125m", "sata_ref_100m",
+	"pcie_ref_125m", "sata_ref_100m",  "usbphy1", "usbphy2",
+	"dummy", "dummy", "dummy", "dummy", "osc",
 };
 static const char *pll_bypass_src_sels[] = { "osc", "lvds1_in", "lvds2_in", "dummy", };
 static const char *pll1_bypass_sels[] = { "pll1", "pll1_bypass_src", };