arm64: dts: imx8-ss-conn: fix usdhc wrong lpcg clock order

The actual clock show wrong frequency:

   echo on >/sys/devices/platform/bus\@5b000000/5b010000.mmc/power/control
   cat /sys/kernel/debug/mmc0/ios

   clock:          200000000 Hz
   actual clock:   166000000 Hz
                   ^^^^^^^^^
   .....

According to

sdhc0_lpcg: clock-controller@5b200000 {
                compatible = "fsl,imx8qxp-lpcg";
                reg = <0x5b200000 0x10000>;
                #clock-cells = <1>;
                clocks = <&clk IMX_SC_R_SDHC_0 IMX_SC_PM_CLK_PER>,
                         <&conn_ipg_clk>, <&conn_axi_clk>;
                clock-indices = <IMX_LPCG_CLK_0>, <IMX_LPCG_CLK_4>,
                                <IMX_LPCG_CLK_5>;
                clock-output-names = "sdhc0_lpcg_per_clk",
                                     "sdhc0_lpcg_ipg_clk",
                                     "sdhc0_lpcg_ahb_clk";
                power-domains = <&pd IMX_SC_R_SDHC_0>;
        }

"per_clk" should be IMX_LPCG_CLK_0 instead of IMX_LPCG_CLK_5.

After correct clocks order:

   echo on >/sys/devices/platform/bus\@5b000000/5b010000.mmc/power/control
   cat /sys/kernel/debug/mmc0/ios

   clock:          200000000 Hz
   actual clock:   198000000 Hz
                   ^^^^^^^^
   ...

Fixes: 16c4ea75 ("arm64: dts: imx8: switch to new lpcg clock binding")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>