arm64: dts: imx8mq-librem5-devkit: Drop custom clock settings

Otherwise the boot hangs early on and the resulting clock tree without
this already closely matches the selected rates (722534400 and
786432000).

  audio_pll2                  0        0        0   722534397          0     0  50000
     audio_pll2_bypass        0        0        0   722534397          0     0  50000
        audio_pll2_out        0        0        0   722534397          0     0  50000
  audio_pll1                  1        1        0   786431998          0     0  50000
     audio_pll1_bypass        1        1        0   786431998          0     0  50000
        audio_pll1_out        1        1        0   786431998          0     0  50000
           sai2               1        1        0    24576000          0     0  50000
              sai2_root_clk       1        1        0    24576000          0     0  50000
           sai6               0        0        0    24576000          0     0  50000
              sai6_root_clk       0        0        0    24576000          0     0  50000
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts

@@ -244,11 +244,6 @@ &A53_3 {
 	cpu-supply = <&buck2_reg>;
 };
 
-&clk {
-	assigned-clocks = <&clk IMX8MQ_AUDIO_PLL1>, <&clk IMX8MQ_AUDIO_PLL2>;
-	assigned-clock-rates = <786432000>, <722534400>;
-};
-
 &dphy {
 	status = "okay";
 };